Something else I noticed, though not sure how easy it would be to modify; if you go to restore a backup, but you had used generalised biffing in your install, the new biffs created by that mod remain in your data folder. I'm assuming this is because it is a simple "delete all except..." type code and the data folder was left out to reduce backup size. Easy enough to delete the biffs at any time, or to uninstall the mod before restoring a backup, but thought it worth mentioning.
Thanks for all your hard work!
Edit: This is for EE, though I imagine it's similar for standard ToB.
Edit 2: I stand corrected; my latest backup restore removed the new biff files. Ignore this post!