Round 2 (166e9f9e) fixed the stash-key mismatch, but @mkoreen's
2026-06-23 bundle showed BS's MQTT project_file arrived 85 ms past the
2.0 s wait timeout (FTP done 00:42:02.509, "No slicer options cached"
00:42:04.509, MQTT 00:42:04.594). Queue item was committed with
settings defaults; nozzle_mapping never made it onto the wire.
Three pieces:
1. _SLICER_OPTIONS_WAIT_TIMEOUT module constant, 2.0 -> 5.0 s. Covers
wireless / loaded-Pi jitter; one-time +3 s cost only for legacy
slicers that never send MQTT.
2. _RECENT_QUEUE_ITEM_TTL fallback: on_print_command retroactively
UPDATEs slicer-driven fields on a recently-committed queue item
when the event wait already gave up. Tracked via
_recent_queue_items dict (30 s TTL, evicted on every queue-add).
Gated on status='pending' so we never race the dispatcher.
Multi-plate covered via WHERE id IN (...).
3. Post-commit last-chance pop. Audit caught a race in (2): MQTT could
arrive during any await inside _add_to_print_queue (wait_for,
archive_print, db.flush, db.commit), and on_print_command would
stash data with no event consumer AND no _recent_queue_items entry
yet. After populating _recent_queue_items, _add_to_print_queue now
pops _slicer_print_options[file_path.name] one last time and
routes any hit through _restamp inline.