that "new" bug is probably just incomplete localization.
I like the concept of this modpack. A few things to consider:
what meat do wolves, snakes, mountain lions, etc. drop if bear meat, venison, etc. are back?
bring back gore blocks? I know TFP removed them due to performance issues but maybe the corpses can downgrade to a gore block after time and then completely disappear after some set time.
I believe TFP retired challenge notes in A20. Perhaps this modpack can bring them back.
bring back the giant hornet and its jar of honey goodness