The injection liquid has to be compatible with the injection parts. Like other chemicals tolulene, xylene, acetone, etc...
Straigh methanol is cheap.. and the amount consumed is so small it doesnt hit the pocketbook hard.
As far as performance.. on my own personal vehicle, it is my belief it runs faster on 93 with alky than it could ion c12/c16. A few runs I did middle last year on c12 netted 190+ intake air temps at 24 PSI. At BG racing it, my intake temps never went higher than 5 degree's above ambient all week long.
mid 10's at 132.. did it in Reynolds.. and repeated at BG

on 93 octane