Hello Brian!
The caps are as far as I know used by many because the hair will be done afterwards depending on the application.
For printing it depends on what the target-resolution is.
You would need to be careful about the hairstyles, thin and stray hair for example is very tough, if not impossible.
You can get decent results but there will most likely be a lot of clean-up involved (=high cost).
Hair is in my opinion one of the trickiest things to get right and too big of a variable for me to feel comfortable about.
It was the reason we decided to hold off on 3D-printing headscans until we can find a fast, workable solution. This is ofcourse dependent on how much time you can spend per scan and qualitydemands.
Another thing to keep in mind is that the needs for coverage can increase a lot if you have to cover the full top of the head too.
Best, Magnus.