There was a tip on using foam inserted in the tires for the same reason, i.e. preventing flat spots.
This can lead to another in the great debate circle. There must be a "flat" spot on the tire, where it contacts the road surface. however it must remain on the bottom of the tire. This is the contact patch, without it, there is no movement.
In an effort to get the most tire to the ground, increase the contact patch, slick tires were made and thus banned by F1 to slow the cars down. That is the reason for the "grooved tires, less contact patch, less stability, less speed.
When our brothers in the aircraft world first received "bulged tires" for models, the cry went up that modern aircraft, due to the tire pressures did not "bulge". Horse Hockey!
Where there is contact, there will be a "flat" spot. You DO NOT want the spot to rotate with the tire, Flat Spotting. caused by braking. But a "flat" spot on the bottom is acceptable.
Don
I know it's only rock and roll, but I like it.