... is how often (or seldom) AR is the #1 in Stafford's reads?

My suspicion is that the ball is supposed to go to Kupp quite often, particularly late in the game, and if he's not free (or if Stafford doesn't think he will be, or runs out of time, etc.) that Stafford then goes through his progression.

From what little I've seen and read it appears that AR is the #1 early in the game more often than later when he disappears.

The tapes of the Bills game confirmed what I was seeing occasionally on TV: AR was getting open after the ball was out or Stafford was chased out of the pocket, back turned to AR.

AR is not OBJ or somebody else. We can't expect him to be. It will take a few games and multiple practice reps where he is involved in the game plan (McVay?) to develop chemistry with Stafford and become a more integral part of the game.

A sidelight: I think it's possible that McVay, in the heat of battle, calling every play, tends to go with what he's more reflexively familiar with. Hence, balls to Kupp, Higbee, and fewer to AR. I've often wondered if he were looking on from afar, so to speak, taking in more of an overview with a real OC calling plays, how his management of the game would be different. He tried it a bit early-on with Coen, presumably, but since?