I did not mean that. The form (non-client) is automatically scaled by the OS. If the DPI changed the size and font and graphics needs to draw "bigger" or "smaller" as per current monitor. And that's not the case..
It would be better you do not use PerMonitorV2 and just use system DPI awareness. That's already a small challenge to properly handle that.
If you then move to another screen with DPI change let the OS bitmap stretch your Form. So it looks correctly sized though a bit blurry.. but better than nothing.
looks like you are on the right path, ensure you change all properties that may scale & that includes whatever font the control may be using. Of course this is impossible unless you a) have source code or b) the control exposes the font(s) and needed properties (for example possibly some offsets).
I have tried your framework by adding some controls of Krool's VBCCR17.OCX, VBCCR17 failed to do auto scale. Can you write a new utility to support VBCCR.OCX? Is it possible without changing source code of VBCCR to make them DpiAwareness to PerMonitorV2?