I'm using vMix with an Acer 23" touch screen. Controlling vMix with touch is very good in most cases.
But the four overlay buttons are very small. It would way better if the buttons have double size.

And please remove the close button from this place, its very dangerous. Why not a little red cross in the right upper corner of the thumbnail window like a normal window? It's intuitive and out of range from the other buttons.