To answer my own question: I would NOT move the bag over to T1 myself if I was flying in economy or didn’t have sufficient status to use the priority check in area. T1 was mayhem with long snaking lines. I don’t think all of it was for AC flights, but figuring out which was the bag drop lineup, etc., would have been stressful and time consuming. It made CDG look tame by comparison… We dropped our suitcase off in the priority area and it was a cinch. The CSA told me that the T3 to T1 transfer (e.g., using the belt at connections there) was quite reliable. Surprisingly, our bag was waiting on the belt at T3 when we got through immigration. It can’t have been more than 15 minutes from the plane to the belt for us.