I don't know if someone has already said this, but when loading optifabric with the create mod, it crashes

its optifine, ofc it would break another renderer

Trying to add compatibility with flywheel is highly unlikely as that is another rendering engine entirely

That’s intented by the fabricators of create

It does "GPU instancing". If you know anything about OOP, instancing is merely creating "versions" of classes to manipulate the code in a much more advanced way. GPU instancing essentially "copies and pastes" instances of the same block/entity so it doesn't have to re-render the same thing over and over.