Reason number million why I don't use the Android emulator - when dragging the emulator between monitors with different scaling - everything freezes to hell. The emulator is to blame of course as a piece of Google's software art, but let's talk a bit about monitors.
Display scaling, and indeed multi-display in general - is some absolutely unsolved area of computer science. Literally everything is wrong with them. Given: 24-inch FHD monitor for games, 24-inch QHD monitor for work, standing side by side. As a user, I want to see on different monitors a picture that in the physical world correlates 1:1.
Imagine, in 2022 you still can't play games on a non-primary monitor without hellish crutches. So from time to time you have to switch between them observing beautiful bugs.
On Windows (almost sure it's like this everywhere) half the applications when they want to get scaling - take it from the primary monitor because why not. For example, Telegram on different monitors displays with different scaling. This can of course be blamed on the fact that Telegram development supports bicycle-writing, but almost everything works like this, that is, in the desktop world this is generally accepted. If you decide to make the FHD monitor primary, then on QHD you'll look at soap in these same applications. Credit where credit is due to Microsoft, their native applications are written excellently in this regard.
This is at least the most notable thing you can notice, but not the only one. Just when you drag a window you see how the left part of the window on one monitor and the right on another are different scales. Some applications crash when dragging because they're shocked: "how is it that scaling changed on the fly". When switching primary monitor, your windows can get lost on some invisible third monitor. On KDE, when I last touched it, I didn't find a normal way to set different scaling on monitors at all. I'm afraid to imagine what it's like on Macs. I haven't had to, but with their approach "don't hold the phone that way" I wouldn't expect anything good there. I'd be glad to be wrong.
In short, my advice - don't buy monitors with different resolutions and don't switch the primary monitor during work. You don't need these problems, believe me.