You'll get an actual user to post soon, but in general, slower twists for lighter bullets as a rule of thumb, and since the modern sabot is typically lighter than a full size slug, I'm thinking you should be kosher.
Now this has me wondering if Savage uses the same twist rate on the 20 Ga.? 'Cause a friend of mine has the 20 Ga. version and it's so accurate it's making me want one. I'd bet that the slower twist really is due to the lighter sabots. Savage apparently knows what they're doing based on what I've seen of those things. I'm starting to have dreams of seeing one in my gun safe.
The 20 gauge Savage has an excellent reputation for accuracy. It is much harder to find reviews of the 12 gauge. A 12 gauge may require a different twist rate to stabilize a sabot. Since they are the only manufacturer with such a slow twist rate, it would be nice to understand why.