Lots to consider. I ran with 22 psi for a weekend. My difference in 1/4 mile times between 19 psi and 22 psi was hundredths of a second. My car was much stronger in the lower rpms and slower up top. The extra heat produced and horsepower consumed spinning the supercharger outside its efficiency range negates much of the power from the extra boost. As long as the fueling and tune are good I wouldn't worry running 22 psi however. The fuel used changes the AFR's. Pure gasoline gives one reading. 10% ethanol leans it out some. 104 oxygenated fuel reads much leaner on the wide band. I like to have AFR's in the high 11 low 12 range. You make more power 12.5 to 12.8. Not advisable. Do you know your AFR's? I'd worry more about the 6700 rpm.

Les