Welcome to the forum!
This question is way over my head. I've never tried to compile Inkscape (and probably won't ever try it, haha).
But I was just curious, so I first opened a program that I use, which is like the Task Manager on steroids (called Process Explorer) to find out if I had any of rundll32 running. No I didn't. Then I opened Inkscape. But I still don't see it.
So my best guess is that it's not supposed to be running with Inkscape.
But you should definitely wait for someone more knowledgeable about this. As I mentioned privately, we might have to escalate this question to developers, but let's see if someone know the answer here