I have a follow-on question: I cannot get Multiplicity "triple click" Ctrl to make both screens 'hot' on my networked X-Plane 11 and Pilot2ATC.
It depends on what 'hot' means here and what the expectation is when invoked.
When triggered, it will send all Primary keyboard input (not mouse) done on any PCs to all other PCs. For example, if I had notepad up on each PC, whatever I type in it on one PC, test sent to all other PCs.
What will not happen is if there is a keyboard plugged into any Secondary, and it is used, it will not broadcast keys to all others - its only the input from the Primary keyboard.
Stardock Support Manager