It's an interesting idea. I am a bit doubtful that you'll get much boost for the IR flash, though. What's it output spectrum? if you put an rm72 over the light source, I doubt you'll get much extra exposure of the film. It'll just have to be tried.

This film has rather limited IR sensitivity. A very deep red flash should be much more effective and not too intrusive. But bear in mind that you probably lose 3 stops of flash power when you gel it.

The reason why the IR flash strategy works well with digital is that the digital sensors are very IR sensitive, so much so that it is a problem. Alas the Rollei film and superpan and the Efke and Ilford films aren't nearly as IR sensitive.