This is just an observation for whatever it's worth, but I just noticed that Settings -> Filetypes may be giving incorrect information.
For example, on my system at the moment, the entry for ODT correctly shows Opens with OpenOffice Writer
but Edit then incorrectly shows all the Actions as LibreOffice commands.
NirSoft FileTypesMan, on the other hand, despite identifying the filetype as a LibreOffice.WriterDocument shows OpenOffice commands in the equivalent of the Actions.
I strongly suspect this is somehow caused by my having several times uninstalled whichever of OpenOffice or LibreOffice is installed and then installing the other and now having both installed. Still the information presented by FileTypesMan seems more correct than that presented by Opus File Types.