I know this is the JAWS group, but this is a workaround for this issue: Use NVDA during gaming.
I have not played with the JAWS screen curtain feature in several years, but if it turns back off upon right click and that can't be changed you're stuck. Under NVDA the screen curtain can be made persistent, and there's even a warning when you do this that you need to remember how to turn it off again to get it out of persistent screen curtain while using NVDA. Of course, if you exit NVDA to go back to JAWS, I believe the screen curtain function controlled by NVDA is turned off.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
One does not discover new lands without consenting to lose sight of the shore for a very long time.
~ André Gide