Ask HN: Customizable Screen Magnifiers for Windows, Linux and Mac?

I'm looking for a customizable screen magnifier for low-vision use. My requirements are fairly straightforward (though maybe not to implement):

- Fast response time and especially low latency on starting magnification; the screen magnifier built into macOS is the gold standard I'm comparing against here (try it with a macOS trackpad and you'll know what i mean). No other magnifier I've tried on Windows and Linux can seem to match this.

- Assignable hotkeys to enlarge certain parts of the screen. For example, I want to bind a hotkey that when pressed, brings up a window in the center of the screen that shows a magnified view of the Windows system tray area. Pressing the same hotkey again should hide the magnification.

That's really all I need. I can zoom in and out as needed very quickly on macOS because the magnifier latency is so low - it's pretty much natural at this point. I've never been able to get the same seamless feeling on any other OS; the only thing the macOS magnifier is missing for me is the hotkeys feature.