Personally, I think you should choose one or the other, or pay for 6 pulls.
Trying to kill two birds with one stone will only delay getting the next truck up there and if we have a lot of trucks show up, well, I'm sure you see my point. Besides, don't cheat yourself of three good pulls. Give Sal as much info as possible to adjust your tune.
One other plus is, once your truck has had three pulls, and it's taken off the dyno for the next truck, you'll have time to pump out the 91 octane and replace it with 2 1/2 gallons of race fuel.
Just my thoughts.
Stewart