Good points, per usual. I very much look forward to seeing how they both perform in live action -when neither is wearing a no contact jersey. Interestingly, that would be for opposite reasons. Has TD improved his pocket presence, reads, decision making, and play making when the rush is live? Does GS's physicality and willingness to run through people to extend plays make him the better overall playmaker in this offense? As you said, there are many factors to consider. The above would be among the most important to me.
It seems that the "separation" between the QBs DB was talking about earlier, assuming he was referring to Devito/Shrader, is no longer as clear following the scrimmages. Or, he is just blowing smoke. I think the reality is probably somewhere in between.