This is a super minor thought, so if it's hard to do at all, it's probably not worth it; but when I was making my Floating Menu Menu Item's the other day, and adjusting the font size, I noticed that it's a dropdown (that can also be typed into):
This was fine when I was setting it to a single known size (or picking one of the defaults); but when I was iterating on trying to find the right size, I was wanting to go up/down by 1pt at a time, and found that it was a bit of a pain having to type the numbers in each time.
I wonder if this could be a combination of the existing dropdown, and a HTML number picker with increment/decrement buttons:
I also noticed that there's a big jump from 10pt to 20pt, after which it goes to 4pt and then 2pt increments. In most word processors/similar that I've used, there are a few more smaller pts available by default; which might make sense here too.
Here's an example from Google Docs that has both the increment/decrement + dropdown UI, and more pts in the list:
