Boil gravity effect on Flavour/Aroma additions

[crapspray]

I'm messing with my IIPA recipe in Beersmith, all grain with 25% DME to bump up the ABV a bit, and I'm trying to figure out where to put the DME addition. Either at the start or the end of the boil. My conundrum is this:

I've currently got the DME addition at the start of the boil, I'm hitting 75 IBUs, and have all my hop additions in the 15-minutes-and-less end of the boil. This is going to be tasty.

BUT, if I switch the DME addition to the END of the boil, my IBUs shoot up into the 90s, which is just too much for my liking. I could reduce the amount of hops I'm using, but I'm afraid it'll reduce my flavour/aroma as well.

So my question is:
Can I get the same amount of flavour and aroma out of less hops if I switch my DME addition to the end of the boil, just like I get the same bitterness from less hops? Or can I leave the DME at the start of the boil to maximise my ratio of flavour and aroma to bitterness?

 

[aiptasia]

I'd just add it at the beginning. Bring your wort to a boil and when you're ready for the DME addition, remove the pot from the heat/flame. Stir in the DME slowly to avoid clumping and then return the wort to the flame. This will help avoid scorching of the wort and unintended malliard reactions against the bottom and sides of the boil pot.

 

[Yooper]

IBUs really are independent of wort gravity, although the IBU calculators don't figure it that way. That's why you have the jump on Beersmith.

You can just add the DME at the end of the boil, and it really doesn't cause the IBUs to jump up like that. Or you can add it at the beginning if you're doing a full boil. It really doesn't matter.

 

[crapspray]

Really? Wow.
All this time I've been led to believe that boil gravity has a direct effect on hop utilisation. Is this one of the disputed areas of brewing science? Why would Beersmith bother with the extra calculation?
I feel like I've just woken out of the Matrix here.