The way blender gather messages to translate is:
1) disable the addon
2) parse all available strings
3) enable the addon
4) parse all strings available strings again and subtract the ones gathered at step 2.
But due Blender bug (https://projects.blender.org/blender/blender/issues/116579) not all addon parts unregistered at step 1, so some addon's strings left out and gathered at step 2 and then subtracted at step 4. At the end, we loose them and they will be missing from resulting translations files.
I've monkey patched dump_addon_messages so it now works a bit more safe:
0) It expects addon to be disabled and Blender restarted after
1) Gather all Blender strings
2) Enable addon
3) Gather all Blender strings again and subtract strings from step 1.
Andrej730