Would you risk it? What would you do?

You can argue semantics and minutia all you want but the bottom line is that cryo treatment is a form of heat treating that makes most if not all steels "tougher" and more wear resistant. A side benefit is stress relief which for certain applications is very beneficial to not have the part "move" under thermal stress. Whether it or another form of treatment such as Meloniting have any benefit, real or imagined, in your specific application is a moot point. The processes work as intended. Everyone needs to decide for themselves if it's worth the time, cost, and hassle to improve the molecular structure of the steel components in their motor or other application.