Two words: Wear (and) tear. If you did this quite often, the sealing surface in the sensor could become worn out/damaged, or the sensor's housing could eventually fail.
Plus... let's say that you remove a sensor to add air. You're going to have to then put it back on. You could lose a little air during that process of reinstalling it.
So much easier to just install the T-Valve, mount the sensor on top, and use the perpendicular stem valve to add (or remove are) as needed.