well, I still think that Qt is the better solution, and so by an order of magnitude :-) it allowed me to write the software, which is being used in production in mac / linux / windows, while doing a ph.d. at the same time ; not sure I could have done the same with any of the other options in there (an older version was using JUCE but it was full of problems ; in particular JUCE's software renderer is much less efficient than QPainter). And for all of REAPER's goodness, it took decades before getting a linux version.

Oh yeah, I agree. It's a good one. Several folks in the comments called out the author for not bringing it up. Personally, I think the author had a bias where any solution had to be close to the size of the native, standalone app.

One thing I wondered about Qt is if there's a way to trim out anything an app doesn't use. Have you seen anything like that?

There's https://qtlite.com

Along with the following shell command :

    grep  --only-matching --no-filename -R 'include <Q.*>'  | cut -f2 -d' ' | sort | uniq

you can quickly see what must stay and what can go