I’m not sure what your use case is - but I’ll also mention in passing that AHUD has a bunch of methods for drawing on the screen. In particular DrawMaterial:
AHUD::DrawMaterial | Unreal Engine Documentation
and the other Draw* functions might be interesting.
The reason I thought of this is because drawing a reticule is a lot easier with AHUD::DrawMaterial than going through UMG, (at least in my opinion).