I've been planning on making a resource pack but the chest model doesn't work. It works in the inventory but it doesn't appear in-game.

Can't seem to replicate the issue with only EMF and ETF, do you happen to have Enhanced Block Entities installed?
Or it could possibly have been fixed in recent versions

I use Forge

Okay, just because EBE changes rendering of block entities, and so breaks EMF models for now, but if you use Forge, perhaps try the models in the latest ETF & EMF