I have done this only on 35mm. Multiple flashes plus long exposures to fill in a room or to light an object with very slow films. The best performance I have had was with an OM4t that did off the film metering, it worked even with films such as kodalith which I shot at ei~3-6.
If you are not shooting people I think a sufficient long exposure under normal room lighting will look the most natural. The darker areas you could possibly paint in with a hand held strobe or diffuse flash light beam.