That’s not even considered a preference, really. Just an expectation and default.
The idea I was trying to mention is removing gamescope from the launch options may fix the issue, as it does with Cyberpunk 2077. Different game, but similar mechanics.
Based on your initial post, it sounds like a multi-monitor setup, so I’m guessing this wouldn’t be an issue if it were one monitor. Of course, you may need more than one monitor, but removing one while gaming should be an option I imagine.