Comparing Time Machine backups with Beyond Compare? Would it be safe to compare Time Machine backups with Beyond Compare? Or would Beyond Compare somehow corrupt the backups? Thanks
Beyond Compare would not corrupt your Time Machine backups so long as you just compare files and folders, but it would certainly corrupt the backups if you use any features which alter your data.
And, from what is on the Beyond Compare web site there is nothing to suggest that it is aware of the specifics of how TM writes to the destination disk.
So between lack of awareness of TM formats and risk of modifying/corrupting the backup, I recommend you not use Beyond Compare.
For functionality and safety, it is much better to use a tool designed for Time Machine.  That means BackupLoupe, as @mmmmmm has suggested. BackupLoupe reads the TM destination and builds its own database of the content.  Under no circumstances can it modify your TM backup.
As well as making it easy to find significant changes, BackupLoupe includes a search capability to assist when finding files to recover.