My Evernote thread CPU burn seems completely random -- sometimes stuck at 5% until I close the app, sometimes none. I've not noticed that it's predictable like any of the recent posts have suggested (e.g., a plain-text note of a few sentences in focus will burn my CPU cycles indefinitely at times, other times, not). Usually (but not always), re-opening the app will make it behave until perhaps a sleep/hibernate cycle?
Anyway, I suppose the devs (if enough are still there) have already fixed it for the next release. In either case, typing in this forum won't likely make much difference in getting it fixed.