diff --git a/csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py b/csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py
index b25b1aea..f9ccffc0 100644
--- a/csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py
+++ b/csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py
@@ -2193,12 +2193,19 @@ class CommandJobBuilderDialog(QDialog):
         """Live, advisory-only OSA-collision warning for
         move_foptz_with_shift's foptz_target field.
 
+        Checked against fosaz's *defined* IN position (its "in"
+        user_parameter), not wherever fosaz happens to be reading right
+        now -- fosaz is normally parked safely OUT except when actually in
+        use, so checking the live position would almost never warn. The
+        real question is "if the OSA were swapped in at its nominal
+        position while foptz is at this target, would it collide", which
+        is also exactly what FlomniOpticsMixin.fosa_in() itself checks
+        (and refuses on) for fosaz moves -- this surfaces the same check
+        here, at data-entry time, for foptz instead.
+
         The move itself stays a plain absolute move (see
-        _queue_action_move_foptz_with_shift's docstring) -- this just
-        surfaces, at data-entry time, the same clearance check
-        FlomniOpticsMixin.fosa_in() enforces (by refusing) for fosaz moves,
-        so an operator can see a likely OSA collision before queuing a
-        foptz target, without the queue action itself blocking on it.
+        _queue_action_move_foptz_with_shift's docstring) -- this is
+        advisory only, the queue action itself doesn't block on it.
         """
         from csaxs_bec.bec_ipython_client.plugins.flomni.flomni_optics_mixin import (
             compute_osa_remaining_space,
@@ -2217,14 +2224,17 @@ class CommandJobBuilderDialog(QDialog):
             if fosaz is None:
                 return
             try:
-                fosaz_val = fosaz.readback.get()
+                fosaz_in = (fosaz.user_parameter or {}).get("in")
             except Exception:
                 return
-            clearance = compute_osa_remaining_space(foptz_widget.value(), fosaz_val)
+            if fosaz_in is None:
+                return
+            clearance = compute_osa_remaining_space(foptz_widget.value(), fosaz_in)
             if clearance <= 0:
                 lbl.setText(
-                    f"Warning: at this foptz target, OSA clearance would be "
-                    f"{clearance:.2f} mm (<=0 = collision risk with a normal OMNY pin)."
+                    f"Warning: at this foptz target, OSA clearance at its defined "
+                    f"IN position ({fosaz_in:.2f} mm) would be {clearance:.2f} mm "
+                    "(<=0 = collision risk with a normal OMNY pin)."
                 )
                 lbl.setVisible(True)
             else: