I have made guisada a few times, but always on the stovetop. I think smoking the meat first might give it a great new flavor dimension. Just don't give it too much smoke flavor, the guisada gravy is delisious and you wouldn't want to overpower it.
I think I will try this myself soon, it sounds good. I think I would reverse sear it by smoking it to a rare condition, cube it, and then sear it in the skillet.