I’d vote for color profiles and DPI awareness as my favorite wish list items. Both of these seem to require a lot of work and refactoring though.
I got curious and went to peek at MS Docs to get some info on how to upgrade existing applications to DPI awareness, and it seems like it requires a radical change in the GUI approach — not only replacing API calls with their new DPI aware equivalents, but also to ensure that every GUI element is refreshed on DPI changes notifications … which I guess would include switching to another monitor, as well as the user changing the Desktop scaling factor manually.
But yes, it would be indeed nice to have DPI awareness, especially for a graphic application, considering that many users will have multiple monitors, high DPI monitors, color calibration, etc., especially if working in the video games industry. These two are fundamental features that affect PMNG at the overall level, since they concern how it fits as an application in the overall context of the host machine, whereas the other features are more on a functionality level, affecting specific operations within the application.