Backup of the file, if it’s already corrupted

This discussion is beyond the scope of this forum. The developers have made their decision. If you have issues with this, please post directly here: Corrupt project preceded by aup3-wal file · Issue #2140 · audacity/audacity · GitHub

If you have a corrupted file, see: Corrupt or Otherwise Broken Audacity Project Recovery

If you have a backup of a project and you are getting interference from your backup service because of the file name, I would think that you can simply rename the file. Everything you need should be in the one .aup3 file.