Scaffolding has one of the most expensive block models in the entire game, and MoreCulling can optimize it a lot. In the worst case, there are 16 useless faces per block that can be culled

Well opengl is already applying block face culling to it. So not really, however I believe it should be culling but is unable to, do to the fact it does not have collisions

Turns out it was not due to the collision, as I fixed that.
I've determined the cause. It believes that the legs have transparent pixels in them. So it doesn't attempt to cull it.
I implemented directional texture transparency in v0.13.0, however that somehow didn't seem to work for scaffolding.

So I believe the cause is due to the side scaffolding texture having transparency between the legs in the texture. I'll see if I have enough time to write code to take that into account.

I've implemented this into the mod. Thanks for the suggestion, this will probably lead to a lot more blocks being culled.
Actually, this seems to have fixes the top of fence posts not being culled when a flower pot is on top.

It will be in the next release.