Thanks for the image. That’s the way I have mine, although I also turn off camera names and borders.This is about as close as you're going to get to what you are asking for.
I've added images of my setup and a mock-up of a simplified layout that would be ideal for me. I realise extra work to the UI might not be an option so that's why I suggested a setting to remove the UI and borders while keeping same window size. The same display option you have when selecting "Full screen video" but without actually using the full screen.

