I mix tyres without problems...

I like a front tyre that feels good under hard braking and a rear tyre that feels good hooking up on the gas.

To me these are very separate, especially at the track where I'm either on the gas or braking, all the time.

I also use a slightly firmer rear than front because in my view if I'm gonna really push I want any 'negative' feedback from the tyres/grip to come from the rear well before it comes from the front.

My 2 cents worth.
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Stop sniffing my ring

MC28SP
KLX110 hotrod
CAG Minimoto
1997 WRX
21 Speed Bike
162 Smurfs