I just switched my laptops and the new laptop runs at 3840 x 2160 resolution. That's optimal. If you try to bring it down, things start looking funny. The problem is that Valentina Pro Studio looks horrible. Widgets cannot be resized and some of them are completely off the screen. There is no way to reset it. I am including screenshots for your convenience. Is there anything that can be done about it?
High-dpi support has received another set of improvements, including support for non integer scale factors commonly used on Windows.
I created a test build with a new Qt version to check if it really helps:
I downloaded this version and it somewhat better, not completely yet. I am including two screenshots. One at 225% screen increase size and the other one at 250% screen increase size as a recommended setting by Windows. This should help you gauge your work on your side.