Hey there, Herstory.
I think that you have been super clear, from the start, that you do not WANT a DADT (don't ask, don't tell) situation. I also agree with you that what he's asking for really isn't consensual nonmonogamy, because if you two don't communicate about the whos/whats/wheres and such, then this all isn't actually consensual. And no, nonconsensual nonmonogamy doesn't tend to go well for relationships.
I'd agree that without communication, this really isn't what most people mean or want when they talk about polyamory. I hear you saying you two have resolved the issues, but honestly, it sounds to me like one big one remains here, which is that you two really don't seem to be hearing each other, and seem to be locked in a power struggle over this. You want one thing, he wants another, and neither of you wants what the other does.
Personally, I strongly wouldn't advise you to agree to anything in a relationship you very strongly do not want. I don't think people agreeing to things they don't want like this is going to create or nurture a healthy relationship. There really isn't middle ground here with something like this where what you each want is simply radically different. It also sounds to me like he still really doesn't ant this. I'd even say what he's saying to you about business partners sounds like....well, sounds like him being manipulative or just trying to goad you in some way. It doesn't sound earnest to me, it sounds...vindictive? I'm struggling for words, but I can certainly say it all doesn't sound healthy or good.
I'm sorry to say this because I know you're invested in this relationship, but. What you two want is just so different -- he still sounds like he wants to be in something monogamous, and you still sound like you don't -- and the communication around all this sounds so broken down or at a stalemate AND some of it just sounds unhealthy in terms of the dynamics when you try and work this out, but it's just not sounding to me like you two are compatible when it comes to a romantic/sexual relationship. I can see that you (I can't speak for him since we only hear from you) have been trying very, very hard, and over a considerable amount of time, to try and make this work and find some middle ground. But I think that despite all of your best efforts, you sound like you're in the same place you started here, where you just don't want the same things, and where neither of you is going to be able to get what you each want or need.
On top of that, something about the way he's framing things with you just does not sound loving or healthy to me. It sounds manipulative. I feel like he knows he keeps offering you something you don't want, like he's stayed pretty snarky about the whole thing, and also like he knows -- or thinks -- you'll probably cave and just settle for what he wants eventually. Or, agree to something that he knows or suspects will make you miserable. It just all sounds pretty dysfunctional and busted to me, which again, I'm sorry to say.
Can I ask you to say some about why you want to stay with this as a romantic/sexual relationship so badly you'd stay in what really feels, to me, like an endless struggle that's always had a bit of a nasty edge to it? On the whole, I have gotten the impression that this relationship has just offered you more struggle and pain than anything good, to the point that it's been outright emotionally abusive. Why stay in this, or stay in this as this kind of relationship? You clearly have interest in seeking out other relationships regardless, so why stay in this one instead of seeking out others where you both can be in them with people who want the same things you do, but also who treat you better?
(In the event I'm just missing the greater value of this relationship, or somehow misunderstanding stuff in a big way, I'd say that at the very least, you two need to pull someone else in to help medicate and resolve this. In other words, I think you're clearly at the point where if you're not ready or wanting to move on, and want to try and work through this, you're going to need a qualified third party to help you, namely, a couples counselor who is both queer and poly inclusive. If that's the way you want to go with this, I'd/we'd be happy to help you try and find someone local to you.)
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. - Margaret Mead