Dark mode image "antialiasing" glitch

I have a series of small PNG images of the alphabet from an old computer game; I want to recreate the font. The PNGs are antialiased to a dark background, so I wanted to give Glyphs edit mode a dark background.

Disappointment #1: I have to put all of macOS into Dark Mode to accomplish this.

Disappointment #2: Glyphs then inverts the images, defeating my purpose of using Dark Mode.

Okay, no big deal, I can batch process the PNGs to invert them, then they’ll invert back to the correct colors.

The big disappointment is the glitchy behavior at high zoom levels depicted here. It looks to me like something involving antialiasing, where a “pixel” is defined in the tiny PNG’s coordinate system rather than the screen’s, as it should be? Maybe that’s way off, but whatever it is, it’s a real drag for my use case.

My next step for now will be to give all the images a dark background, but it would be nice to have the whole UI be dark — and it’d be nice to control that independently of macOS, too.

That is not true. You can assign a background color per master in Font Info > Masters > Custom Parameters.

That is true. It does make sense if your image is a scan of a black glyphs on white background. That would look terrible in Dark mode. But if the image is the content, it doesn’t make much sense. I’ll see if I can find a solution.