Production, sure. Limited, probably not. You don't want to shoot minor (9mm) in Limited (huge disadvantage), so the 12 rounds in the .40 model will put you at yet another disadvantage against those of us with 22 rounds in the mag. Even if you could get a mag extension (don't know - do they make 'em?), I doubt you'd have similar capacity.
You're right about IDPA.
From an ergonomics perspective, I've never been a big Sig fan. Lots of metal above your hands, odd controls. Honestly, you don't see a large number of Sigs in USPSA, but I don't attribute that to any one single factor. If the gun feels good to you, and you're confident handling it, it'll make a fine Production gun.
And if you're going to do that, then get the .40, load to minor, and shoot production with bigger holes.

jr