At 10psi a 50/50 mix of C12 and 94 pump is a proven SAFE mixture. This will leave you some room for any mistakes in tuning or while riding at low altitudes going up to the riding area.
10lbs on straight good pump fuel is easily doable... at 6-10k. however with all the crap out there now we are all running a gallon of 110 to 10 gallons of pump just to be safe.
Recently I have been running straight VP 100 @ 11-12 lbs 9000-12000 in elevation, and no issues. No det, plugs are perfect, EGT's good, checked wash with scope and everything is beautiful. Forearms hurt from holding on so tight.