You are right models usually don't have the BFC meta but most software assumes the bfc information only affects parts, so anything using the top level parts can be non bfc-ed, as-long it doesn't use mirroring (although you can compensate for that).
In the end it depends on how you set up your renderer, if the resulting mesh is at part level you'll need a fully bfced tree of dat's to make the whole mesh render with culling, but if you are writing a state renderer you could enable/disable culling while you go, it won't be fast though
My post was assuming the mesh approach.
In the end it depends on how you set up your renderer, if the resulting mesh is at part level you'll need a fully bfced tree of dat's to make the whole mesh render with culling, but if you are writing a state renderer you could enable/disable culling while you go, it won't be fast though

My post was assuming the mesh approach.