It's really too bad that modern tires are the way they are.
They stick in the hot, the cold, the wet, the dry, last reasonably well for the level of performance that they yield.
But, like any MC tire of any era, too many miles straight up really squares off the rears.
But the very rubber composition that makes them work so well, is very counter productive if one tries to reshape them to get rid of the squaring.
For that reason, I really liked my old school tires of the 70s.
In comparative terms, they did not really stick, and they didn't last all that long.
BUT it was ever so easy to reshape a squared off rear with a body file.
That ancient old school carbon black based rubber would shear off real nice.
Set it up on the centre stand, put on the throttle lock, and let her run in 1st gear at 2500 or so revs.
In short order, a nicely shaped rear tire again.
(Remembering always to work the file in a "pull" mode and never "push" - rather a deadly rocket if it grabbed and got away on you)
In reality, I most happily accept that I can't reshape my modern era incredibly good rears as they square.
However, I have found that lots of track miles does a wonderful job of preventing squaring from occurring.
So, I strongly recommend the prevention method.