Just to clarify: When you say “full screen” what do you mean? In Windows you can click that little box in the upper right and make it “full screen.” Or you could drag your Cubase window over multiple monitors, then drag your mixer wherever, and make it almost full screen.
The full screen we are addressing is Steinbergs “full screen” mode selected by right click a blank area on the mix console. Are you saying you can keep a VST on top of the Steinberg “full screen mode” after clicking anywhere on the mix console?
Personally I don’t have an issue with this because of my 4 monitors, only 2 have the Cubase Window stretched over them. The other 2 monitors are for Mixer1 and Mixer2 both in full screen mode set to the appropriate monitors. The other reason I only keep the Cubase window in 2 of the 4 monitors, is that Steinbergs full screen mode will cover up the 12 Cubase drop down tabs.