In D22468#496052, @ngraham wrote:

I'm not sold on the proposal to use 1.25x increments, personally. For my personal use case, I like using 1.1x (13" 1080p screen) and I wouldn't want to lose that. Screen size and DPI combinations are so variable that I think it makes sense to support a higher level of precision. Apple can get away with their very low configurability because of tight control over the hardware that allows them to avoid selling machines where a given option wouldn't work.

That said, I could get behind 0.25x increments if there's some "advanced" page or mods in the GUI that exposes 0.1 incrememebts, or even a spinbox or text box or something.

Either is better than 0.2 increments though. As pointed out, that missed the all-important 1.5x.

Windows 10 scaling allows for 1x, 1.25x, 1.5x, 1.75x, 2x, 2.25x, ... scaling. While KDE doesn't have to be aligned, I think Windows devs were onto something:

• limited number of options decreases the likelihood of users picking 1.1x or 1.4x which may seem like a good fit, but produce less-than-ideal results
• limited number of options allows testing apps easier for all possible scaling options
• still a good enough granularity for vast majority of users