There is an episode of CYBI that covers this in depth, I don't remember off the top of my head what the math was, but they figured out a system to convert whirpool hops on a professional system to a homebrew setup. Maybe one of the firestone walker eps?
Also, McDole did say he would remove all of the early hop additions (using hopsacks) to avoid further isomerization during the whirlpool/hopstand.
If I run across it again I will post a link