I've been at this for nearly two days now, so it's time to ask for help.
Following the instructions on this Stack Overflow answer, How to convert TTF to FNT with Fontforge, I've tried saving my font as
.fon instead of
.fnt as instructed in the answer, but the file is always corrupt.
Windows doesn't understand
.fnt files natively, so I'm not sure if my conversion to that format worked, as described in the original SO question.
I've also tried every online converter there is. The 1 site that offered this option returned a corrupt file.
So I was thinking maybe it's not possible, but then I found that someone had converted tahoma.ttf to tahoma.fon, so I know it's possible. I verified it is a bitmapped font.
I'm somewhat comfortable with fontTools, but I've only used the pyftsubset. I'm far from an expert on fonts.
Any help or nudge in the right direction is appreciated.
I've also tried these suggestions, but without instructions I couldn't figure it out.