Mixing in 100 octane(or higher octane) isn't going to yield anymore power. Infact, you may make less. The higher the octane fuel the slower the flame front spreads meaning that timing must be advanced to maintain MBT. The DME will not automatically advance timing to account for this.
"I'm not surprised you get along well with all the other neighbours. If you put fifty children with Down's syndrome in a room there is going to be a lot of hugging." David Thorne