Also, if you are coding native windows apps, how are the existing native UI frameworks failing you? What drove you to roll your own?
About your second question, I was using win32, in the past I used winUI, but always wanted HTML-CSS for manage the UI, but without the JS overhead.
I started building it and now I think it's at good level and usable. I published some showcases, still thinking if and how publish it
Also, if you are coding native windows apps, how are the existing native UI frameworks failing you? What drove you to roll your own?