I'll be interested in some responses from fast stroppers, but I really don't think stropping does anything but remove debris (metal shavings if it was just honed, soap from the last shave, etc.). I don't think you can whip the blade over the strop in such a frenzy that it would heat up enough to alter the metal state.

I can't strop fast. Period. And I have been doing it for 2 1/2 years.