You can use one, but most people use a flat file. It works as the frets are already radiused and the fret profiling file should smooth out any slight unevenness. Just be as even as you can with the amount of strokes in each location.

Stainless steel is very hard, so I'd recommend using a diamond levelling file. You'll also need decent paper for smoothing the frets after filing and reprofilling. I'd start with P240 and work up to finer grits from that (or use micromesh after P800). It's also going to take ages to get each one smooth again - I'd allow at least an hour per fret to get rid of all the scratches, as that's what it took me on a Warmoth neck with S/S frets (and that was without having to smooth the fret ends off as well as they were already OK).