Very faint shadow information might get bloomed out.
Reversal processed film, colour or B&W, might have plenty of density to warrant two or more exposures.
And of course many spatial exposures can be used to extract all the resolving power of the film and avoid aliasing.
1. Not in my experience, though I use lenses that are very modern and don't flair much. As long as you're not clipping any of the sensor channels, you'll have *lots* of discrete tone values for shadows. Your experience may vary depending on the quality of the lens you're using.
2. I process a lot of C-41, E-6, and BW and have yet to run across a frame where I thought I could get a better result by doing multiple exposures, though, again, I run very modern equipment, which performs significantly better than stuff from now going on 20 years ago. Could there be emulsions/frames that could warrant more than one exposure? Sure, though, in my experience, that's a very rare exception. Modern equipment does not have the same performance as old equipment, so comparing the two is fraught with all kinds of potential issues. "Low dynamic range" on modern equipment is very relative to other modern equipment. Compared to stuff from even 10 years ago, it's actually very performant. Even Canon, the laggard of the all the camera manufacturers in the dynamic range department generally has both more resolution, and dynamic range improvements with every single camera release, so while they're generally behind the likes of Sony and Nikon for dynamic range, old film scanning equipment is still the same as it was back in the day, meanwhile, digital cameras have seen incremental improvements every couple years for a long time now, and those improvements really start to cumulatively stack up over time. Going back and looking at the output from a Canon digital camera from 10-15 years ago and one from today... The difference in dynamic range, noise levels, and color rendering is startling.
3. True, doing multi-exposure can gain you more resolution, and if you really need that and don't mind spending a huge amount of time working out all the additional intricacies that something like that will introduce, knock yourself out, however, in my experience, for the average shooter, 20-30MP, or about 6000x4000 pixels is plenty for most uses, and things like aliasing aren't really an issue unless you're using a camera that doesn't have an optical anti-aliasing filter (most digital cameras do). In all honesty, overall it's cheaper to just shoot a larger film format than to try to keep extracting ever more detail out of a smaller film format. The vast majority of film shooters today don't have the technical competence to put enough resolution down onto film to make it worth trying to extract much more than a standard 20-30MP from 35mm film, and those that do, prefer to do their own so that they control the image pipeline.
