We use RV for a lot for writing notes on Shotgun videos and its been very useful but it would be great if it could be more robust.
The main thing is that it's not easy to see what annotations you're going to attach with a note. If you don't have "Automatically Mark Annotated Frames" turned on, there doesn't seem to be a way to know which frames have annotations until after the note is submitted. Even then, deleting them is awkward. Though you can clear an individual frame, you can't remove a single image mark and have to remove them all at once.
Ideally, you could see a clear indication of where your annotations are and an easy way to remove the annotation and mark together. Also the menu option for annotation that says "Clear all drawings" isn't clear, because it sounds like every frame would be cleared but it seems to only work on the current frame, like the Clear Frame button.
The other thing that would be beneficial if possible is having more tools. Similar to the line, rectangle, circle and arrow tools from screening room. When supervisors use screening room they often like to use these shapes for convenience, and it would be a big help to have them in RV too.
I hope this is all clear, but I can elaborate on it if necessary.