Octane Question

Looking for some advise. I have 1997 Johnson 35hp 2 stroke 3 cylinder that is sitting at 180 psi compression. It will turn 6700 - 6800 RPM's. It's been tuned to run on 100 LL avgas mixing amsoil 32:1. My question is, as a contingency plan, if I was ever in a situation where I was out of 100LL and couldn't get it, in a pinch could I use Boostane Octane booster with 93 octane pump gas and not hurt the engine? Obviously, mix it at a ratio to get it to 100 octane. If so, should I over shoot to 102 octane???? Should I use pump 93 Octane with ethanol (since 93 non-ethanol is almost impossible to find in my area) or use a 91 non-ethanol (it is plentiful). Thanks in advance. Hopefully I'll never have to go this route.