OK now the dirt comes out
What engine mods?
Down shifting is probably the answer anyway if you are using hi test. Octane booster generally isn't needed in a street bike unless you are running super high compression ratios.
The problem with the clutch as I see it from here is that with the excess heat in the drive train after all those miles, the pushrod for the clutch elongates from the heat and the adjustment is out the window now. That's why I suggested another adjustment. Always do the adjustment cold and it will change and move further away from the bar when hot.
How about the clutch action after it cools down, it it OK then?
ALSO, what trans lube and primary lube are you using?