Thanks a ton for the suggestions, they didn’t entirely work for our setup given what demands we have on it, but they almost worked and with a final piece of the puzzle I got it working! 
Essentially what we do now is to forgo the UI movie render queue entirely and trigger it with Movie Render Queue in Runtime in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer Community
So now I can do blueprint setups like you suggested properly and implement checks to make sure I don’t render any unfinished frames!
Again, thanks a lot!