For example, Moticons replaces font renderer with it's own version of it, and it doesn't save ResourceLocation from original fontRenderer. Because of that, fat textures might not be used.
There is two ways of dealing with that, that I do see:
- Patch that classes. It could be done using whitelist of classes that needed to be patched, or just patching evrything wich is dumb.
- Patch FontRenderer constructor, so it will replace ResourceLocation if it points at default texture
Or you can just replace default font texture, but why would you do so?