Would I be able to follow my own advice?
Jesus... the only thing I can hope is I never have to answer that. Curls and Freckles are my world. I can't see any scenario where things can go that bad, and I hope that I never do. However, I have been married to Curls for fifteen years and we have three daughters. If she told me tomorrow that I had to choose, I would choose her. It would be a horrific decision to make and I would never completely forgive her for putting me in such a position, but we have kids together and we have a very long history together whereas my history with Freckles is comparatively short. I recognize that as our relationship grows and matures, things will become more muddy in this respect, but for right now I would make the hard decision to switch things back to the way they were.
I'm so sorry you are in the position, and I hope that you can pull things through.
First off, let me say, it sounds like the three of you are in a good place and that's awesome. In all truthfulness, I am a bit envious. However, having been "Freckles" in a triad that didn't work, let me say if my guy had informed me that I had been so disposable in the event wifey became unhappy, there would have been no triad. I get that you know it would hurt like hell to dump Freckles, but you obviously have no freaking clue as to what it is like to be the person who is sacrificed. Being the only male in the triad, you will never be in that position, but try to picture yourself in a triad where you are one of two guys and disposable.
In my case, although wife did give him ultimatums, my guy refused to choose. He understood I was a live human being with genuine feelings and felt responsible and guilty as hell for inviting me into situation that turned to crap. That said, the situation was becoming untenable, and eventually, the wife did her own dirty work and asked me to leave.
Fast forward, a year after I left and two marriage counselor's later, the separated and are in the process of divorce, in spite of two children. Why? Not because of me - although wife likes to blame me - but because she wouldn't own her choices and behavior, couldn't understand why he couldn't simply unlove me, as if it was as easy as flipping a switch, and refused to communicate in order to reach any kind of mutual understanding. Apparently, she had a history of not owning choices and behavior, and not communicating before I ever entered the picture. Couldn't do it to save her marriage either.
And in case you are wondering, they have been separated over a year, and while he and I are slowly rebuilding our relationship, we live in separate cities and see each other about once per month. We both have had a lot of grief to digest, and right now, his main focus are his kids - as it should be.
But I will reiterate, if he had ever acquiesced to her ultimatum, there would be no relationship rebuilding at this point.
I hope Freckles knows that your choice is already predetermined if this scenario should arise.