Are the Bilstein HDs valved even more 'pedestrian' than the B6es, or are they basically the very same thing (I had the HDs on my A2 GTI 16V, and yes they were a very reliable damper!)?
Also, being very unfamiliar with all of the inter-mountain and Pac West US stage rallies, I did notice some of them DO have LONG, multiple tarmac stages in the route.
My guess is that ONLY the TOP, best funded, crews actually change out their full setups between the gravel and tarmac stages, and then only if there are services right before and after these stages.
The only time I've seen an actual tarmac stage in the U.S. was when the old Maine Forest Rally used to have the 'downtown' stage through Rumford, going right through the 7 Islands/Cascade paper mill in town, which went away 18 or more years ago.
For that, even the top crews of that time did not change out the suspension, and only some even bothered to change to tarmac wheels/tires (and most of those who did, just used max performance, or autocross level donuts, NOT actual Michelin tarmac rally tires).
Since it was the final stage as well, most crews just figured that their gravel rubber was worn down enough to act
sort of like narrow slicks. LOL
I DO realize that you were speaking to TOP LEVEL, WRC/Euro Championship competitions, where YES, they
ALL change out
everything for mixed surface rallies.
But they also get the cooperation of the organizers in making sure the stages are split evenly, and that there ARE sufficient services between the two changing surfaces to switch everything over.