Actually, I did not find that to be required. I shut down active, then logged into standby and simply changed it to active, logged in again, no issues, as they were already synced.
I wish this syncing process was automatic, thats what I never understood about management HA, but it was manual probably since the beginning. I cant say that as a fact, but I know 100% its been that way for probably 20 years now, at least.
Edit: I could be wrong about sync part, at least doing it manually, though I was never able to actually confirm this for certain. I know for example, if you log into active one, shows standby is synced at that time, but then if smart console stays open for say 10 hours, it still always shows sync time from 10 hours ago, at least in my lab, so would be nice if someone could confirm for sure how that process works.
Andy