I'm not an expert, but will chime in because that's what this forum is for! LOL
In my early talks with VP guys, I determined I should chose fuel, not so much for power, but for fuel consistency that would help prevent detonation. I started with VP's C10 mixed 50/50 with 91 pump gas. Then in teardowns saw that the 500/550 squish shelf really isn't prone to detonation anyway.
I now use V98L in 5 gal cans, just a good clean, reasonably priced fuel for my needs. Again non ethanol. As Mike mentioned these sealed cans are good for at least 2 years, and as everyone agrees purchasing in 5 gal cans is best as you can see the date.
I'm not sure why you feel you need more octane, but my feeling though is the 750 chambers may be more prone to detonating (depending naturally) so a lead component would help. What Frank suggests would work, for me as well, but my local guy always has the 98. Some really fast superbikes here run pump gas with an octane additive, go figure!
We found with Tyler's FZR the one fuel that made power is VP's U4.4 oxygenated. I'm not sure whether it would aggravate detonation, but it's a great fuel. Stinks like hell though!