We have had the McVeggie in New Zealand for a while now - They even included it in our "Kiwi Burger" range. I think it's off the menu now but easily the best burger I have had from Maccas.
I like this idea a lot, just tried it now however and the UI is a bit too slow for how fast I like to switch between apps, espically on multiple desktops - takes about a second to show up and swaps to the active monitor instead of staying on the main like command+tab does. Will follow this!
For the active monitor issue, I have never tested on multi-monitors (I personally switched back to single-monitor after years of multi). Could you please open a ticket? It may be an easy update