diff --git a/install_gnome_extension b/install_gnome_extension
new file mode 100755
index 0000000..fad96f2
--- /dev/null
+++ b/install_gnome_extension
@@ -0,0 +1,107 @@
+#!/bin/bash
+# Install/update a gnome-shell extension from the shared applications
+# directory into the user's local extensions dir, and enable it. Shared by
+# install_gtile and install_tactile -- see those for which UUID/build was
+# vetted compatible with this rhel9 / gnome-shell 40 desktop.
+#
+# Usage: install_gnome_extension <uuid>
+
+UUID="${1:?Usage: $(basename "$0") <uuid>}"
+SRC="/sf/bernina/applications/${UUID}"
+EXT_DIR="${HOME}/.local/share/gnome-shell/extensions"
+DEST="${EXT_DIR}/${UUID}"
+
+log() { echo "$(date '+%F %T') install_gnome_extension(${UUID}): $*"; }
+
+# This runs at login via autostart, right when /sf/bernina (a Kerberos-secured
+# NFS4 mount, sec=krb5) may still be settling its GSS context for this brand
+# new session -- retry briefly instead of permanently giving up on a
+# transient "not there yet" (confirmed intermittent gTile failures previously
+# had no logging at all here, so a one-shot failure like this could never be
+# told apart from a real missing-source case; see gtile_link_migration memory).
+tries=0
+until [ -d "$SRC" ]; do
+    tries=$((tries + 1))
+    if [ "$tries" -ge 10 ]; then
+        log "source $SRC still not found after ${tries}s, giving up"
+        exit 0
+    fi
+    sleep 1
+done
+[ "$tries" -gt 0 ] && log "source $SRC took ${tries}s to become available"
+
+# PSI's home-sync (linux_home_links.yaml) links this dir to the SMB network
+# drive, but a known depth-nesting bug in that tool leaves it a broken
+# symlink (missing a "../../../" prefix) -- fall back to a plain local
+# directory rather than failing the install.
+if [ -L "$EXT_DIR" ] && [ ! -e "$EXT_DIR" ]; then
+    log "$EXT_DIR is a broken symlink ($(readlink "$EXT_DIR")), replacing with a local directory"
+    rm -f "$EXT_DIR"
+fi
+
+# Clear anything GNOME Shell's own extensions.gnome.org auto-update check
+# may have already staged here before allow-extension-installation (set by
+# the main startup script) had a chance to stop it -- a stale staged build
+# would otherwise still be sitting here ready to silently swap in on some
+# future shell restart, superseding the pinned version reinstalled below.
+rm -rf "${HOME}/.local/share/gnome-shell/extension-updates/${UUID}"
+
+src_version=$(sed -n 's/.*"version": *\([0-9]*\).*/\1/p' "$SRC/metadata.json")
+dest_version=""
+[ -f "$DEST/metadata.json" ] && dest_version=$(sed -n 's/.*"version": *\([0-9]*\).*/\1/p' "$DEST/metadata.json")
+
+reinstalled=false
+if [ ! -d "$DEST" ] || [ "$src_version" != "$dest_version" ]; then
+    mkdir -p "$(dirname "$DEST")"
+    rsync -a --delete "$SRC/" "$DEST/"
+    glib-compile-schemas "$DEST/schemas" 2>/dev/null
+    log "installed version $src_version to $DEST (was: ${dest_version:-none})"
+    reinstalled=true
+fi
+
+# A plain `enable` is a no-op if the extension is already enabled -- the
+# normal case every login -- so it does NOT make gnome-shell pick up a
+# version this script just rsynced onto disk above (extensions aren't
+# hot-reloaded on file change). Force a disable/enable cycle whenever we
+# actually changed what's on disk, so the running session matches disk
+# immediately instead of only from the next full login onward (confirmed:
+# this exact gap is what left saresb-cons-05 running a stale in-memory gTile
+# version even after the rsync above had already put the correct one back
+# on disk).
+if $reinstalled && gnome-extensions list --enabled 2>/dev/null | grep -qx "$UUID"; then
+    gnome-extensions disable "$UUID" 2>/dev/null
+fi
+
+# enable the extension (needs a live gnome-shell D-Bus session, i.e.
+# org.gnome.Shell.Extensions already registered -- also not guaranteed yet
+# this early at login, so retry briefly before falling back).
+enabled=false
+tries=0
+until gnome-extensions enable "$UUID" 2>/dev/null; do
+    tries=$((tries + 1))
+    if [ "$tries" -ge 5 ]; then
+        break
+    fi
+    sleep 1
+done
+if [ "$tries" -lt 5 ] || gnome-extensions list --enabled 2>/dev/null | grep -qx "$UUID"; then
+    enabled=true
+    [ "$tries" -gt 0 ] && log "gnome-extensions enable succeeded after ${tries}s"
+fi
+
+if ! $enabled; then
+    # shell D-Bus interface still not reachable -- fall back to writing the
+    # enabled-extensions list directly; gnome-shell picks this up itself once
+    # it (or its extension-directory file monitor) is ready.
+    log "gnome-extensions enable unreachable after ${tries}s, falling back to gsettings"
+    python3 - "$UUID" <<'EOF'
+import subprocess, sys
+uuid = sys.argv[1]
+current = eval(subprocess.check_output(
+    ["gsettings", "get", "org.gnome.shell", "enabled-extensions"]).decode())
+if uuid not in current:
+    current.append(uuid)
+    subprocess.call(["gsettings", "set", "org.gnome.shell",
+                      "enabled-extensions", str(current)])
+EOF
+fi
diff --git a/install_gtile b/install_gtile
index 7aa2534..cc405e1 100755
--- a/install_gtile
+++ b/install_gtile
@@ -1,73 +1,4 @@
 #!/bin/bash
-# Install/update the gTile gnome-shell extension from the shared applications
-# directory into the user's local extensions dir, and enable it.
 # Compatible gTile build for this rhel9 / gnome-shell 40 desktop lives in
-# /sf/bernina/applications/gTile@vibou.
-
-UUID="gTile@vibou"
-SRC="/sf/bernina/applications/${UUID}"
-EXT_DIR="${HOME}/.local/share/gnome-shell/extensions"
-DEST="${EXT_DIR}/${UUID}"
-
-if [ ! -d "$SRC" ]; then
-    echo "install_gtile: source $SRC not found, skipping" >&2
-    exit 0
-fi
-
-# PSI's home-sync (linux_home_links.yaml) links this dir to the SMB network
-# drive, but a known depth-nesting bug in that tool leaves it a broken
-# symlink (missing a "../../../" prefix) -- fall back to a plain local
-# directory rather than failing the install.
-if [ -L "$EXT_DIR" ] && [ ! -e "$EXT_DIR" ]; then
-    echo "install_gtile: $EXT_DIR is a broken symlink ($(readlink "$EXT_DIR")), replacing with a local directory" >&2
-    rm -f "$EXT_DIR"
-fi
-
-# Clear anything GNOME Shell's own extensions.gnome.org auto-update check
-# may have already staged here before allow-extension-installation (set by
-# the main startup script) had a chance to stop it -- a stale staged build
-# would otherwise still be sitting here ready to silently swap in on some
-# future shell restart, superseding the pinned version reinstalled below.
-rm -rf "${HOME}/.local/share/gnome-shell/extension-updates/${UUID}"
-
-src_version=$(sed -n 's/.*"version": *\([0-9]*\).*/\1/p' "$SRC/metadata.json")
-dest_version=""
-[ -f "$DEST/metadata.json" ] && dest_version=$(sed -n 's/.*"version": *\([0-9]*\).*/\1/p' "$DEST/metadata.json")
-
-reinstalled=false
-if [ ! -d "$DEST" ] || [ "$src_version" != "$dest_version" ]; then
-    mkdir -p "$(dirname "$DEST")"
-    rsync -a --delete "$SRC/" "$DEST/"
-    glib-compile-schemas "$DEST/schemas" 2>/dev/null
-    echo "install_gtile: installed gTile version $src_version to $DEST"
-    reinstalled=true
-fi
-
-# A plain `enable` is a no-op if the extension is already enabled -- the
-# normal case every login -- so it does NOT make gnome-shell pick up a
-# version this script just rsynced onto disk above (extensions aren't
-# hot-reloaded on file change). Force a disable/enable cycle whenever we
-# actually changed what's on disk, so the running session matches disk
-# immediately instead of only from the next full login onward (confirmed:
-# this exact gap is what left saresb-cons-05 running a stale in-memory
-# version even after the rsync above had already put the correct one back
-# on disk).
-if $reinstalled && gnome-extensions list --enabled 2>/dev/null | grep -qx "$UUID"; then
-    gnome-extensions disable "$UUID" 2>/dev/null
-fi
-
-# enable the extension (needs a live gnome-shell D-Bus session)
-if ! gnome-extensions enable "$UUID" 2>/dev/null; then
-    # shell D-Bus interface not reachable yet (e.g. very early in session
-    # startup) -- fall back to writing the enabled-extensions list directly
-    python3 - "$UUID" <<'EOF'
-import subprocess, sys
-uuid = sys.argv[1]
-current = eval(subprocess.check_output(
-    ["gsettings", "get", "org.gnome.shell", "enabled-extensions"]).decode())
-if uuid not in current:
-    current.append(uuid)
-    subprocess.call(["gsettings", "set", "org.gnome.shell",
-                      "enabled-extensions", str(current)])
-EOF
-fi
+# /sf/bernina/applications/gTile@vibou (shell-version includes "40").
+exec /sf/bernina/bin/install_gnome_extension "gTile@vibou"
diff --git a/install_tactile b/install_tactile
new file mode 100755
index 0000000..d8cee8e
--- /dev/null
+++ b/install_tactile
@@ -0,0 +1,6 @@
+#!/bin/bash
+# Compatible Tactile build for this rhel9 / gnome-shell 40 desktop lives in
+# /sf/bernina/applications/tactile@lundal.io -- version 27 (extensions.gnome.org
+# package 40260), whose shell-version list covers 3.32 through 44, including
+# this desktop's 40.10.
+exec /sf/bernina/bin/install_gnome_extension "tactile@lundal.io"
diff --git a/startup_bernina_terminal b/startup_bernina_terminal
index 6c80204..a8ad878 100755
--- a/startup_bernina_terminal
+++ b/startup_bernina_terminal
@@ -203,7 +203,12 @@ set_gnome_keyboard_shortcut 'dark screens' 'xset dpms force off' '<Ctrl><Alt>d'
 # reason for it to be on when every extension this desktop uses is already
 # managed by hand.
 gsettings set org.gnome.shell allow-extension-installation false
-install_gtile
+# Logged (unlike a bare call) so an intermittent skip/fallback here -- e.g.
+# /sf/bernina (Kerberos NFS4) not yet reachable this early at login, or
+# gnome-shell's D-Bus Extensions interface not registered yet -- leaves a
+# trace instead of silently vanishing, since this runs unattended via
+# autostart with no terminal to watch.
+install_gtile >> "$HOME/.install_gtile.log" 2>&1
 dconf write /org/gnome/shell/extensions/gtile/resize21 "'3x3 0:2 0:2, 0:1 0:2, 0:2 1:2, 0:1 1:2'"
 dconf write /org/gnome/shell/extensions/gtile/resize22 "'3x3 1:2 1:2, 1:1 1:2, 0:2 2:2, 0:1 2:2'"
 dconf write /org/gnome/shell/extensions/gtile/resize23 "'3x3 2:2 2:2, 2:1 2:2, 1:2 2:2, 1:1 2:2'"
@@ -219,7 +224,15 @@ dconf write /org/gnome/shell/extensions/gtile/resize29 "'3x3 2:0 2:0, 2:0 2:1, 1
 # every other preset-resize-2N sibling was untouched and still works fine)
 # -- reset it back to gTile's own default rather than hardcoding a value
 # here, so this self-heals regardless of what that default actually is.
-gsettings reset org.gnome.shell.extensions.gtile preset-resize-21
+# NOTE: `dconf reset`, not `gsettings reset` -- gTile's schema is a
+# relocatable one bundled inside the extension itself and never registered
+# system-wide, so plain `gsettings` (run outside gnome-shell's own process,
+# which loads it internally) can't see it at all ("No such schema",
+# confirmed by hand -- this line was silently failing every single run).
+# `dconf reset` only touches the raw key/value store, no schema needed --
+# gnome-shell's own GSettings wrapper then falls back to the compiled-in
+# default the next time it reads the now-unset key.
+dconf reset /org/gnome/shell/extensions/gtile/preset-resize-21
 
 # Second gTile preset set: a 4x4 grid on <Super><Shift> + the right-hand
 # key block, laid out to spatially match the keyboard (row of keys top to
@@ -260,22 +273,52 @@ dconf write /org/gnome/shell/extensions/gtile/resize13 "'4x4 0:0 3:3, 0:1 2:3, 0
 dconf write /org/gnome/shell/extensions/gtile/resize14 "'4x4 1:1 3:3, 0:1 2:3, 0:1 0:3, 0:3 0:3'"
 dconf write /org/gnome/shell/extensions/gtile/resize15 "'4x4 2:2 3:3, 2:3 2:3, 2:3 0:3, 0:3 0:3'"
 dconf write /org/gnome/shell/extensions/gtile/resize16 "'4x4 3:3 3:3, 2:3 2:3, 2:3 0:3, 0:3 0:3'"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-1  "['<Super><Shift>7']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-2  "['<Super><Shift>8']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-3  "['<Super><Shift>9']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-4  "['<Super><Shift>0']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-5  "['<Super><Shift>u']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-6  "['<Super><Shift>i']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-7  "['<Super><Shift>o']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-8  "['<Super><Shift>p']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-9  "['<Super><Shift>j']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-10 "['<Super><Shift>k']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-11 "['<Super><Shift>l']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-12 "['<Super><Shift>semicolon']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-13 "['<Super><Shift>m']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-14 "['<Super><Shift>comma']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-15 "['<Super><Shift>period']"
-gsettings set org.gnome.shell.extensions.gtile preset-resize-16 "['<Super><Shift>slash']"
+# NOTE: `dconf write`, not `gsettings set` -- gTile's schema is bundled
+# inside the extension and never registered system-wide, so plain
+# `gsettings` (run outside gnome-shell's own process) can't see it at all
+# ("No such schema", confirmed by hand). These 16 lines used to be
+# `gsettings set` and were therefore silently failing every single run --
+# the resize1-16 grid layouts above were being written fine (dconf write
+# never needed the schema), but the keybindings meant to trigger them never
+# actually got assigned, leaving preset-resize-1..16 at gTile's factory
+# defaults (<Super><Alt>KP_N / <Super><Control>KP_N) instead of this
+# right-hand block. This is almost certainly why this second preset set
+# looked like it "didn't work" while the numpad set above (which only ever
+# needed dconf write, no keybinding reassignment) did.
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-1  "['<Super><Shift>7']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-2  "['<Super><Shift>8']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-3  "['<Super><Shift>9']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-4  "['<Super><Shift>0']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-5  "['<Super><Shift>u']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-6  "['<Super><Shift>i']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-7  "['<Super><Shift>o']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-8  "['<Super><Shift>p']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-9  "['<Super><Shift>j']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-10 "['<Super><Shift>k']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-11 "['<Super><Shift>l']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-12 "['<Super><Shift>semicolon']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-13 "['<Super><Shift>m']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-14 "['<Super><Shift>comma']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-15 "['<Super><Shift>period']"
+dconf write /org/gnome/shell/extensions/gtile/preset-resize-16 "['<Super><Shift>slash']"
+
+#install/update and enable the tactile extension (a second, simpler
+#grid-tiling extension alongside gTile above), then pin its keyboard
+#shortcuts to its own shipped defaults so they self-heal against the same
+#kind of stray-override drift documented for gTile's preset-resize-21.
+# `dconf reset`, not `gsettings reset` -- see the note on gTile's
+# preset-resize-21 above: tactile's schema is bundled inside the extension
+# and never registered system-wide, so plain `gsettings` can't see it.
+install_tactile >> "$HOME/.install_tactile.log" 2>&1
+dconf reset /org/gnome/shell/extensions/tactile/show-tiles
+dconf reset /org/gnome/shell/extensions/tactile/hide-tiles
+dconf reset /org/gnome/shell/extensions/tactile/show-settings
+dconf reset /org/gnome/shell/extensions/tactile/next-monitor
+dconf reset /org/gnome/shell/extensions/tactile/prev-monitor
+dconf reset /org/gnome/shell/extensions/tactile/layout-1
+dconf reset /org/gnome/shell/extensions/tactile/layout-2
+dconf reset /org/gnome/shell/extensions/tactile/layout-3
+dconf reset /org/gnome/shell/extensions/tactile/layout-4
 
 # gnome terminal color profiles: install Solarized Dark/Light and Spacedust
 # (plus a "1-Spacedust" copy that sorts to the top of the profile menu) if
@@ -337,5 +380,5 @@ command -v notify-send >/dev/null 2>&1 && notify-send -u low "Bernina Terminal"
 
 # make rhel9 text larger and rely on default dash, no extra cluttering dock.
 dconf write /org/gnome/desktop/interface/text-scaling-factor 1.25
-dconf write /org/gnome/shell/enabled-extensions "['appindicatorsupport@rgcjonas.gmail.com', 'gTile@vibou']"
+dconf write /org/gnome/shell/enabled-extensions "['appindicatorsupport@rgcjonas.gmail.com', 'gTile@vibou', 'tactile@lundal.io']"
 dconf write /org/gnome/shell/disabled-extensions "['dash-to-dock@gnome-shell-extensions.gcampax.github.com']"