I don't like simple looking suggestions that implies big work behind the scene, especially when already great work has already been and is still been done.
So let's say this is simply a thought that crossed my mind.
It is often a headache to place the OSD elements on the screen, to avoid conflict with the standard Canon display items, or at least part of them. Moreover, we are often experiencing flickering with some those items, when it is not possible to avoid drawing even on a part of them.
So, would it be possible to work with standard Canon items display off mode and let the OSD to draw itself those items too? If the OSD draws everything, it would be easier to place all the items on the screen to avoid conflicts, especially if it would be possible to draw the standards items a bit smaller.