Hopback IBUs

[DusqoFDB]

Did a quick search but couldn't come up with much of use.

Has anyone had any lab tests done on beers that get a hopback addition and gotten any useful data that could suggest what kind of utilization your are getting from the hopback?

I would guess it would be minimal or about the same as a whirlpool addition which I always just assume about a 15% utilization for ibu calculation.

Any feedback appreciated.