Been using 91 octane which is the highest we can get here in northern CA. Started using it early on to stop the "run-on" and backfires but I don't think it really helped much, if any.
Since I prefer to take my cans to be filled in the back of my pickup, and since that pickup has a chip and requires higher octane, it also makes it more convenient to fill the cans then continue on to put gas in the truck. Taking the cans to be filled in our SUV makes for unpleasant fumes inside.
Phil