Tom, that should be fine so no reason for the difference there. Low octane fuel has the light ends that can be the difference between fire and no fire in a marginal case.
I'm going by my experience and dyno testing of pump gas and haven't come across a situation like yours personally. Not to say that it can't happen, obviously, but that I haven't seen it yet. I've seen a couple of cases that looked like an octane issue but turned out to be something else, usually ignition related.
