Running separate windows of separate applications (or even the same one) on more than one monitor is no problem at all - I've used that setup more than 10 years ago with my (then new) Merlin (e.g. Workbench on RTG, Diskmaster :lol: on ECS).
Splitting one window over separate monitors is not possible, as has been stated. I have no idea whether P96 or Cybergfx support multiple RTG cards though...
PS: I just remembered I actually had three monitors connected: by using some weird overscan setting it was possible to freeze the output on an A2024 Hedley and switch back to a PAL screen and work there. :banana: