Of all the clutches I've replaced the springs on with stainless, I've had no problems whether they've been SBK, ST, M's, slippers or conventional.
The polished springs on the market tend to be within a gnats of the standard ones tension. I've also used some "natural finish" springs and these have appeared a little heavier.
When you say you've replaced the master as well as the slave, if the master is a Brembo radial, the bore on those is bigger than stock. This will further decrease the effort being offered by the slave cylinder.
IMO, you shouldn't worry too much. Get out and try it and see how it goes.
You could put a washer under the spring caps, but if you are getting slip, then I'd check the clutch plates and pack thickness first.
Increasing the pack thickness with a couple of thicker plain plates will increase the preload on the springs a little and is "technically" a better option than using washers..............c'mon it's a Ducati
