Some have said that during normal shifting there's like a one or two grind just before it slides into gear. I have noticed that a little with a stock setup. I was wondering if an upgrade to a dual disk clutch would make it any different becuase the synchro now has to speed up or slow down two plates instead of one?

Define "Normal shifting"? Is this while the truck is in motion or during start up? What shifts is this occuring 2-3 3-4 etc...? I never had any grind unless speedshifting..oops. This would only be caused by bad syncros(rare), extremely low fluid or your slave is not engauging properly with the pressure plate fingers.
To answer your question, no...I personally experienced no issues with the SMF set up in relation to the syncros.