It's a suggestion that is worth considering. Here's my two cents.
I don't know if it's needed yet. I've only seen two threads so far. It might be needed later if the popularity of these machines increases.
One problem with subdividing any forum is the potential for brain drain, as some very smart people with narrow fields of interest will only stay in their subforum.
Benchtop Machines already has three subforums. Right now, I'm hesitant to do anything that would further fragment this forum.