yes race. it's the only version they make for 26". not cracking, but actual slices from rocks and stuff. the corner knobs do seem to be wearing quickly, even for a race compound. what tire sealant are you using?Race version I presume? Funny you mention that, but my tires have had tons of superficial cracking throughout, yet I've experienced no torn knobs or significant leaking, although I top off pressure every week or so to be safe.
Not to be pedantic, but something seems off. Like there is accelerated moisture evaporation from rubber or breakdown of oils causing the rubber to crack. I've been wondering about presenting as a warranty issue, but haven't for 2 reasons. First is that the tires are working and haven't self destructed. Secondly, Michelin's website is les poo poo.