On track you will be using the edges, not the middle.
As andyaikido said, the ‘squairing; might cause handling problems mind.
Best to buy a new one, like I said , it will be the edges you will be predominately using, so it is not as if you will be wearing the road-useful part of the tyre anyway … also this way you get to have a cool looking ‘chewed’ tyre on the road for the rest of the tyres life
