Agree with toggle. It would allow sneak attack to be used with whichever hand attack you wanted, in combination with whatever special abilities, and allow allow for sneak attacks to apply during AoOs.
The currently-implemented toggle that swaps main hand attack to dual wielding happens almost instantly, so a similar sneak attack toggle would take up way less time then having to find and click a sneak attack button every single turn.
Also it needs to change to dealing Xd6 instead of 1d6*X damage, so that dealing <5 damage with sneak attack happens less often. And the "to hit" indicator should explicitly say whether you have sneak attack (figuring out if my ally is technically within 5 feet is difficult).
