If anyone has more optimisation tips, I'm more than happy to listen.
set(ENTITY,UNLIT | NOFILTER);
ENTITY.emask &= ~DYNAMIC;
When your block-models have more than 1 skin, f.i. the grass-dirt-block, they render way slower than models with only 1 skin. Combine both textures, grass and dirt, into one (bigger) texture, this will increase your fps remarkably.