If sanding is needed between coats due to accidental imperfections, how long would one generally have to wait until sanding? Wet or dry sand?

Check an inconspicuous area with your finger nail to see how soft the surface is, semi hard to hard, it can be sanded dry or wet. Try sanding dry and if your sand paper clogs up to fast, then do it wet. This paint take 24 hrs to cure but can still be a little on the soft sidedays, also depending on they temperature.