Everything we have done so far doesn't require optifine. That's one thing I know we don't want to require for people because of performance issues for lower-end PCs. But I greatly appreciate your feedback because I'm on the same boat with just making a massive texture pack which allows us to have 100 custom mobs with dynamic animations but the file size limitation kind of screws us over.
Yeah after your first comment i dug into YouTube and found some videos on it! so thank you so much for your help! Timber Forge has a great playlist for this
Yeah i used Mr Garetto's Armor stand maker but thats the problem im running into. Could you maybe talk a little deeper about the custom Item models, doesnt that require Optifine? Currently Working on a server idea and trying to make it the most user friendly experience.