Quick Question: is the Aevitas perk tree suppose to 'de-age' animals that multiply by the fertility perk? Because it causes problems with mountable animals as they 'de-age' when they 'breed' and undergo mob mitosis. I'd just throw the idea out there if possible, to have the perk not make mountable mobs 'de-age' or breed by the perk as it is rather problematic when your mount de-ages into a baby while you are riding it. You can't remount until it grows up again. I know, I could tweak the configs to effectively neuter the problem, but it would be rather bothersome to have to play in the menus every time I go to use a Horse or Donkey. This is just a small quality of life thing I noticed.

Next update will prevent ridden entities from being affected.