My two cents, for whatever it is worth. Yes, hierarchical poly-fi Vs do work.
My wife and I tried cuckolding, but the wife needed more of a relationship with her paramour. She is inherently demisexual and sapiosexual, and is more compatible with a long-term relationship then a one-night stand. As her hubby, I love to play matchmaker for her. Matchmaker is defined for us as I do the introductions and step back and let nature take its course.
The last gentleman that I played the matchmaker for my wife turned out to be a hit for the wife and me. I will call him David. He approached me to ask for my permission to date my wife. After we talked at length, I found him to be respectful, upfront, and a real nice guy, at that. I told wifey of this gentleman who wanted to date her and I gave my blessing. I drove her to her first date with him.
That date lead to many more dates, some with me, others without me. I thought it was important for me to give them space to find intimacy, and for them to bond as a couple, which they did over time. I was there to share the special occasion when my wife confessed her love for David. I was proud of both of them.
So my wife became the hinge in a hetero MFM poly-fi V. However, we all agreed that the poly relationship needed to be adjusted after a period of time. David came to me and wanted to know if I would give my blessing for our hinge to wear his collar. My wife let me know that if I agreed with her taking David's collar that our poly V would become hierarchical, with David becoming her primary and I secondary.
I asked David what that would look like to him becoming her primary and I secondary. David simply replied that he would become the decision-maker in all things. I gave my blessing. To be honest, it was the best decision that I made, that my wife made, to allow David to be elevated to her primary. The intimacy that my wife and I share is simply off the charts. I was never happier for myself, for my wife, and for David.
No question, to make this work for all involved took communication and respect.
On a side note, David told me that he would provide me with an example of what it would look like as my wife's primary after he collared her. I told him that I would appreciate that very much. He provided me with two lessons on his decision-making authority after he collared my wife. I will leave those for another entry.