I did some high speed runs(????) with my XF200 to see what mod helps.
First run 127.5 and 35 jets 16 tooth front sprocket Yosh loud ass can
72 MPH indicated

Second run same as first except 15 tooth front sprocket 73 MPH indicated.

Third run same as second run except stock can back on 75 MPH indicated.

Speedometer is off by about 8 percent high according to my GPS so top speed true is about 67 MPH at 8k RPM.

The Q sounds so much better now so I staying with the stock muffler.