Heat can help, I've had good luck with something as simple as a soldering iron. Some consideration is needed though, as the sole won't appreciate heat that much.
Allen screws are quite helpful, in that the stripped hole is a perfect guide for the drill.
Sometimes hammering a slightly larger Torx into the stripped Allen can give enough purchase to break the screw free.
One method I've had good luck with is to put a smallish hex nut over the stripped screw, and then run a weld bead into it, fusing the nut to the screw. The concentrated heat helps, and you get decent purchase to unscrew with the nut.