Plasma Desktop: Block compositing for fullscreen only

Hi Everyone! I have been an opensuse user for many years, although I haven’t visited for a while and was forced to create a new profile in these forums. I am trying to recreate in Leap 15.4 with KDE Plasma desktop what has been my normal working environment since before there was Leap. My most recent installation was Leap 15.2 (I skipped 15.3). In prior versions I would have a desktop cube with four virtual desktops. Each VD would be assigned a specific function with assigned applications. The trick here is that one of those desktops would be running Windows in WMware Workstation as a full screen app. My virtual machines do not play nicely with Nvidia and compositing, and I recall that there used to be a setting to turn off compositing when full screen. As I said, this worked for me for years.

Now the cube is gone, bit I can make Slide work.

But the option to turn off compositing while full screen is also gone. I guess the expectation is that one is supposed to use Window Rules to manage that kind of thing, and I can certainly create a window rule that turns off compositing, but it turns it off everywhere whenever the full screen application is running. This is not what I want. What I want is to turn off compositing when the full screen application has focus.

There is also a script called Autocomposer in the KDE store, but it also turns off compositing everywhere. So I am stuck. Right now I am back to manually toggling compositing using Alt-Shft-F12, which is far from ideal.