Hop Back / Hop Rocket when to use

I am looking to get a Hop Rocket soon.  For my hoppier beers I want to experiment with hop backing the whirlpool.  I use a counter flow chiller.  When and how long are people hop backing?  The whole chilling process?  10- 20 min. at a certain temp.  I am familiar will all the research of the different temps to whirlpool your hops at etc…  for plumbing purposes shouldn’t I have a diverter that will switch the hop rocket off and
finish chilling.  Please advise