The unmerged file reads the integration outcomes and the determined group, neither of which the P1
merge changes, except each image's mosaicity, which the batch headers carry and the merge rewrites.
UnmergedMtz builds the file without it on a second thread, and SetUnmergedMtzMosaicity fills it in
after the merge, so the file is the same bytes as before.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C
leonarski_fandClaude Opus 5.5
92877e5eb7