My Krita View3D plugin creates a docker with an OpenGL viewport and seems to only work with Krita set to “OpenGL” mode (last time i checked anyway). I haven’t actually investigated the “why” since i’m using Linux as my main OS and barely boot Windows.
It is most likely some conflict between using native OpenGL and ANGLE. In theory it shouldn’t matter since i’m creating a new context and all, though i don’t know how deep ANGLE goes (i never used it) - perhaps i’ll move all the OpenGL stuff to the C library (the plugin was originally Python-only) at some point in the future and use Qt just for obtaining a window handle (or pass a window handle to Qt and hope for the best).