Is this possible? - Limit to only one occurrence of "Projector"

[RobertWilliams]

I find that when my system is lagging or CPU usage is running high, one of the culprits is I opened multiple Projector windows. Would it be possible to limit the system to only one projector window and if it is requested that a warning message could popup telling the user that there is already one running in the background?

I tried to use the setting below but I am still able to open multiple projector windows.