Painter 21 on my PC, win10, 27" 4K monitor, OS set to 150% font size,
has double height toolbar and brush selector bar available that works well.
However other panels, bars, lists, etc. do not, and are very tiny and hard to read...see example .jpg attached, where toolbar size is AOK but recent brush bar list is way too small to read/see when it could be a similar 2x taller if available as a user choice.
So, suggestion is to expand GUI choices for better user visibility that at least matches the other GUI toolbar choices.