Do you mean the size of the actual window? And which application (costume manager / stage manager)?
If Windows isn't doing that for you (I think Windows 8 can do this), the only thing I know how to do is adjust all the font sizes upwards - maybe I can put in a setting for that. WinForms dates back a long time and wasn't designed for high-DPI monitors

Yeah, the window becomes extremely compact.

I run on Windows 10 so it adjusts its own programs but not external ones. If you could put in a setting that'd be great. So we're clear, this is what it looks like with display scaling disabled:

And with it enabled (too big for Imgur to do the whole desktop so here's it with some icons):
