Does Cubism render 0% items, calculate their physics?

This might be more related to the program you use your Cubism project with. For example Live2D. I just realized this while I was making this post. But maybe it isn't. I am lost where I should ask about it.

So let's say I have...:
dress A
dress B
dress C

Dress A and dress B has their own legs. Legs as in socks, stocking, whatever.
But dress C uses A's legs.

Is it better to copy and paste A's legs and call it "C's legs", effectively making a new part and just having the whole set ready for expression toggle, or should I make a toggle to only hide the legs, basically making the whole thing more modular and sorting it out in the expression?

Version A: Where I just have a separate piece for the whole dress. This is cleaner. One expression, one full variation. But results in duplicated parts. If Cubism/Live2D doesn't render and calculate 0% items, the more items does not more load on the software in the end. But if it does, this is just not efficient.

Version B: This version would have only one part, even if it shared. And the switch would be done through an expression. This complicates the model and project, but it sounds more "efficient". But, I am not sure how Cubism/Live2D handles things.

If I hide a part to opacity 0%, are they unloaded, or do they still render just remain invisible?
Since I can't toggle part visibility otherwise - as far as I know.

I mean I know version B is 100% works but it's so much more work and thinking. Which is fine if I must, just saying.

Thanks!