Lars Ingebrigtsen has an interesting post about proportional fonts in the Emacs mode line. His post shows the same mode line in both fixed and proportional fonts. There’s no arguing that the proportional fonts look better and that they allow for the display of more information on the mode line.
Still, the suggestion to move to proportional fonts is an old one and has always been controversial. There are some serious objections. For one, things like the point position are updated with every character typed and that can cause the mode line display to shift right or left.
Ingebrigtsen says that they’re running a month long test on Emacs Master in which proportional fonts on the mode line are enabled by default. They’ve installed a fix for the problems of things like the point position and the developers are hoping that that will address previous objections to using proportional fonts.
Regular readers know that I don’t care much about this sort of thing. All in all, I’m happy with a fixed width font mode line but I don’t find the idea of proportional fonts objectionable either. If you’re tracking Emacs Master, be sure to let the developers know what you think.
UPDATE Emacs 28 Master → Emacs Master.