That's the name of the mod is "Infestation potion mod": https://modrinth.com/mod/infestation-potion-mod
This works just fine with the pack so far. I found Allays and I was so disappointed I couldn't build an xp farm (you fixed the level xp issues already too).
Side note: I adjusted the settings for "carry-on" to pick up most blocks, and it replaces the cart thing for spawners. Now you just pick it up and run haha
#Potion of Infestation
indigo knoll
river haven