Isn’t it construction/carcass vs compound ?.Hard carcass or just the hard tire? They have never had a choice when it comes to carcass. I am certain that the harder carcass was implemented after 2021 due to the delaminating issues and at the request of ktm. The only reason they were necessary is because of the added load of ride height and aero. The benefit was instant to the euro bikes and the decline of Yamaha and Honda. Marc has always chose tires the rest of the field didn't, but that wasn't carcass related just harder or softer rubber.
MM often in his pomp rode a soft compound tire and got it to last longer than others. The construction/carcass is I had thought a different thing which has been controversial, including two separate rider votes to change the original tire, to Stoner’s and Lorenzo’s disadvantage as I recall. Michelin even brought the tire which had been Rossi’s preference pre-season to an American round to test, which the other riders including MM thought was nice work if you could get it. I don’t think MM cared because his preference was similar to Tossi’s.