I’d like to bump it up 2 points for about 10 gallons. None of those boosters would work?
From 91 to 93? Can't really be done (legally) with anything from an auto parts store. Most have disclaimers saying that a "point" for them is less than (R+M)/2. Like 2 points equals 0.2 increase of (R+M)/2.
The only thing that really works is blending some fuel that has a higher octane rating. The octane boosters that work independently of bulk octane rating are tetraethyl lead and MMT. The former is not street-legal and the latter can't really be used that much.
Some mentioned toluene. Ethanol would also boost octane rating, but most fuel in California is already E10. I've seen some gas stations that sold 94 octane (R+M)/2, but that was usually from blended 100+ octane street-legal racing gas.