Having the probe too close to the bone will cause a reading higher than the actual meat temperature. In a situation where someone is concerned that their butts will not be quite done in time, I don't see a problem with double wrapping in foil, adding a tiny amount of liquid inside (water or apple juice) and finishing in the oven at a higher temp than the stock SI controller is capable of. At that point, they have absorbed all of the smoke they are going to, and it is just a matter of getting them through the stall, and making them tender.