Unless Chronometer switches to using the debuff duration stuff, it most likely won't work with the new, odd, way that HM refreshes, since you don't actually cast it now. (well you kinda cast it, getting a gcd, but no mana usage, and I don't think the normal spell casting events are fired)
I'm going to give ClassTimer,
http://wowace.com/wiki/ClassTimer, a go tonight/this weekend and see how it does instead.
As for tracking the strength, I don't think that information is easily available, a mod will have to track all the combat & filter out the hits that'd count for increasing. With the new combatlog distance changes, it becomes even more complicated requiring sync data.