I had completely forgotten to try the test build until your reminder. I think the answer to your question is kinda / sorta. Meaning:
> Sometimes it takes 2 clicks on the Start button to get the start menu to open
> The left Windows key seems to work reliably, whereas the right Windows key does not work, i.e., no matter how many times I press it the start menu flashes but does not stay open.
> On monitor #2 pressing the Start button seems to work reliably to open the start menu on monitor #2. Pressing the left Windows key reliably opens the start menu on monitor #1. And finally pressing the right Windows key opens the Windows 7 start menu on monitor #2.
I think it is odd about the Windows 7 start menu, as I could find no setting in the Start 10 settings that allows one to opt to have the Win 7 start menu.