Originally Posted by mtbikerinpa

Generally speaking it is more favorable to go completely down to bare metal. The old paint can have imperfections hidden within until the top coat sets up, showing pits or lines. At very worst it could be hiding rust/corrosion underneath.
I prefer a wire wheel in my angle grinder for this. It takes paint off in no effort at all but it wont damage the steel. A complete frame strip with that takes about 30 mins relaxing.

For in between coats, the wet sanding should be just enough to 'haze' the paint enough that you see one continuous surface. No 'orange peel', or low spots.