Hi there!
First (sorry, wee bit offtopic!) => I can't help compliment you with this amazing mod, we (= gf & me) have so much fun with this critter. It's just.. completely crazy (in a good way!). "Trash mod" indeed, lol!
The issue
So.. my friend Aya discovered the quarry upgrade (and boy, that's just awesome!). Of course the only caveat here is that as the hole gets deeper it'll take the rats longer to bring their loot up and store it in the 'quarry chest'. So my friend studied the upgrades and discovered 'Platter': "Rat will transfer entire stack of items at a time". However, this doesn't work while digging: the rat(s) still insist to collect 1 item and then bring that back upstairs.
Expected behavior
We kind of expected the rat(s) to collect a whole stack of items (so: continue digging for a while) and then store the whole stack in the quarry.
Details (versions)
Forge: 47.4.10
Rats: 1.20.1-8.1.3
Thanks for reading!