LAX:
I really wish people would start new threads instead of posting all of their questions on this thread!

Here's the trick: Set a Desired rendering resolution in your Window Layout, and then they will all technically be the same size, and therefore mouse repeat will work as desired.
Lax, I moved the thread as I see your point.

Size is not the issue, this is more of a feature thing.

I'm trying to find out if I could make session 4 the primary as my mouse is over that window and then change the mouse to primary over the first session. Understand that session 4 does not move from the monitor it's running on. Currently, it will only mouse repeat if I'm over the first session. I hope that clears up the question.