You can't hit the 32 degree timing from the 6k-8400k range on 91 but I have also logged fuel with 91 and 95 and 91 on a 50-60 degree day if run hard a few times was still able to hit 28-30 degree timing target. With more pulls or a summer day, 91 would be likely in the under 25 degree range but 60 degrees without heat soaking the car with too many runs, 30 degrees should be quite attainable.
93 pretty consistently hits 32 degrees unless temps are above 90 with quite a few hard pulls and then it dials back to 26-27.
Using 95 octane (race fuel mix) is the only stuff that virtually always hits the targets in cold or warm and consistently.
I am not saying I am sure but datalogging since he is doing it already with a 199 dollar BT tool would save a lot of headache and speculation as he can assure his cams are hitting their timing marks and A/f was good etc