first wort hopping

[denverhoo]

sort of trendy these days and something I want to try. How can we do this with beertools? assume a first wort hop addition on first runnings, then a second batch sparge, so the first wort hop addition is maybe a half hour before reaching boil. I like to boil a solid 20 minutes before my 60 minute hop addition. But if I input the FWH at 110 minutes---I get a number that I am given to understand doesn't reflect the reduced utilization that somehow magically happens with first wort hopping.

Any ideas?