Why are settings parameters in gestures different than in UI?

For example: in the normal UI, you can change font weight by .25 increment and can go well above +3, using the fine tuning dialog. But for gestures, you can only change by 1.0 increment and it only goes -1 to +3, even though it's using the same dialog. I'm sure there's a code reason for this, but on the outside it seems like an arbitrary limitation. Similarly, contrast in gestures seems to be in a different scale entirely.

While I'm here, I'd like to put in a request for gesture support for switching to specific typeface. Basically, I use different fonts for normal and night mode and it'd be great to change to dark mode and preferred font for dark mode with one tap.