The first and only time I've seen it (so far) was on the Kampenhout track in Belgium. They had three zones of different surfaces: two corners with cobbles, and a small section with wood.
One of the cobble sections was a scary one imo: shortly after the landing zone of a jump. It isn't a very demanding jump, but every time you get it wrong you'll be praying for the shock towers not to break
I really liked the track though (it teaches you not to be too ambitious on jumps
) and I can see how the different surfaces add to the fun and challenge of the track. Especially with the 2WDs, right after one of the cobble sections was a straight, a quick corner and another straight. Getting away quickly is essential, but taking the wrong line or being too greedy means you'll only wear your tires and lots of wheelspin.
All in all, yes, you do need to take tire wear into account, but if a low bite/grip section is put somewhere in the track it can only add to the challenge of driving there (quickly)!
