No, I haven't asked Michelin to pro-rate a tire for wear and probably won't. Most importantly, I never run my tires down to the 2/32" wear bars.
Most look at a written warranty and think, well, 60kmi warranty, tires wore out in 40kmi, so Michelin should give me 33% off the net cost of new tires. It doesn't usually work that way.
Yes, many years ago, I was a Goodyear tire store service manager. Literally every customer who tried to get a pro-rated replacement went away mad, swearing never to buy Goodyear again.
Maybe, the reason is the tires must be evenly worn down to the 2/32" wear bars and accompanied by the receipts to prove regular rotation. Then, the warranty pro-rate was calculated against a full-list-price, which no one should ever pay for tires. Tires are usually sold at a discounted price. Then, the mounting and balancing are at full shop cost. Anyway, when the pro-rated tire warranty cost was applied, it was pretty close to what they would have paid for a new tire anyway.
Your results may vary.
jack vines