Interesting article…well at least the part I skimmed…haha. They lost me early on because I feel like it’s all about common sense honestly. Sure I can create a beer with a gazillion IBU but if it’s all late hops of course it won’t be “bitter”.
I create my IPA by feel and experience along with what my palate likes as others have stated. I’m usually in the 25-35ish IBU range with 60 minute bittering hops. A little higher if I use first wort hops. Then I focus more on “pounding” it later. Last few IPAs haven’t had in middle boil hops to speak of. I feel like the FWH replaces the 20-30 mins addition with more flavor and a bit of additional bittering.