Are stainless valves harder on stock iron head seats?

I've said it before and I'll say it again--Stainless steel valves will stop exhaust valve seat recession which will negate needing hardened seats installed in your J heads. I have witnessed this many times. Valve seats "sinking" or becoming recessed is due to little chunks being ripped from the seat every time the valve opens-kinda like everytime a sparkplug fires a "chunk" of electrode is removed. Stainless alloys seem to stop the fusing and "ripping" of the exhaust seat thus stopping the recession. Iron and Stainless get along very well. J.Rob