TM Stock
The TFWW wheel is more properly a radiused face versus radiused edge (with flat face), or flat face with one or two flat sides. The TFWW wheel is much closer to the shape that I've used for wheel dressing - slightly radiused face generated by wheel or diamond dresser - so I suspect any change in shape due to heating is not an issue. For a flat faced wheel - whether square-edged or radiused edge, it seems like a bit of a traverse across the face cancels any issue, which is pretty common technique.