Race Gas from my view...
My 2 cents and take this advice for what you paid for it....
ALWAYS run at least 50% 100-104 race gas in a forced induction car on the race track. Always. Many tunes are not perfectly designed for the tortures of the track in addition to a lot of pump gas octane issues, the cheapest insurance you'll find for your motor is a 1/2 tank or more of race gas.
Additionally. 100 octane has very little negative power impact on a tune that was designed for 91. So run 100octane even if 100% mix. Anyone that says they can feel a power drop from 100octane, I call horsepucky. It barely shows up on the dyno let alone the SOYP. Any power degradation you feel on the track is due to the add'l heat not higher octane fuel.
Now, some race gas carries oxygen by weight. For instance, my FAVORITE fuel is Sunoco GT260 Plus 104 octane. It's another one of those magical liquids that's permeated with glorious track pixie dust... similar to redline shockproof oils... straight from the heavens....
anyway...We all know that between the two inputs that go into a motor, fuel and air, air is the only one of the two that is scarce, as fuel supply is infinite. Well, what a nice thing that your infinite fuel supply carries some air with it!!! The only catch is that your tune needs to be adequately "rich" if you're going to run oxygenated fuels, since air is taking the place of some fuel for a given unit of the fuel...
Do your best to avoid leaded fuels. The lead will foul a narrow band in half a shake of donkey's tail. that said, if in a pinch and it's between running straight pump gas or a mix of pump and leaded race gas, RUN THE MIX OF LEADED RACE GAS. If you end up running 110 octane leaded like a lot of tracks have available, and you end up with a full tank of it, you will lose some power and likely foul the 02 sensor... still cheap compared to a motor. 110 octane is just too much octane for good power for all but the most extreme builds in Lotus 2ZZ-Ge land...
Regarding using the ECU to sense knock and pull timing like running 87 octane or chancing pump gas at the track... Well, let's chalk that idea right up there with "New Coke" and "sub prime mortgages"!:facepalm

The knock routine on this ECU/firmware is quite crude and ill tuned from Lotus. Don't trust it. It's bad. Run the right fuel...
-Phil