This isn't unplayable, but many of my friends have been struggling with starting our pack, I managed to get it running and did some reading
In lieu of explaining basic problem solving skills, it seems that either theres a problem with iwannaskate's model mappings, or the application of rainbow coloring thru jelly acts as a package bomb of sorts (total guess), resulting in this COMEDICCALLY large line of render thread warnings for basically any entity that isn't using the Living Entity Renderer

Forge: 43.2.6 (1.19.2)
AM: 1.21.1
Citadel: 2.1.3-1.19

Here's an excerpt from latest log:
LolLmaoEven.txt

NOTE: This isn't fixed, but the problem seems to be caused more by the skate mod and thus I will be forwarding it to that repo