You said Coopers told you they adjust their IBUs with isohop. Across the range on their website, there's only a couple that have the same IBUs.
Assuming they do as you said, and simply evaporate the same worts they produce for drinking as homebrew, then by my calculations about 3/4 of the Coopers range of kits is isohopped, perhaps more.
Unless there's a way to remove bitterness...
Sorry mate I'm not with you.
You asserted that kits (implication being all kits) are bittered with isohop rather than real hops (implication being solely bittered with no real hops in sight). The question is how do you know that?
I've then suggested to you that not all kits are necessarily bittered without real hops to which you've asked for a reference. Fair enough. I provided a fairly substantial one which suggests that Coopers (at least) use real hops in the kettle and MAY adjust SOME kits with isohop.
This means your assertion that all kits use isohop (and by implication from your wording do not use real hops) is incorrect.
Instead of answering which kits do use isohop as their sole bittering agent and how you know this, you then use my reference to somehow indicate that only one coopers kit uses no isohop. What does same ibus have to do with it?
You are not making sense. Please go through from point a to point b. I have no doubt some kits, maybe even most kits use iso as a sole bittering agent. That's not enough to assert that all do nor is it enough to assert that none use real hops. Some at least (and a very popular range at that) DO use real hops.
We could continue this argument for some time if you like. Before we do, using a reference other than me, could you please tell me which kits use isohop as their sole bittering agent and use no real hops (whether flowers, plugs or pellets) in their wort/extract production?
I'm happy to email coopers again and clear anything up but until I hear anything I won't be making claims beyond my knowledge. Not sure why you are.