I know how complicated this question of commitment and official vows and such can be. I am in a similar situation, even though we never spoke about such detailed actions yet. But I know that the thought of 'how to make this situation we are in to have a more legal and 'fixed' character' has crossed the mind of everyone involved. Along the lines of children, illnesses and responsibility we discusses the downsides and possibilities already at least once. So congratulation on having such specific ideas of how to act on the wishes of the persons involved.
I am a bit astonished about the reaction of your wife. I thought that my husband was surprinsingly ok with everything that was and is going on with my boyfriend, but your wife seems to top even that. Good for you and her
But I am wondering if there was never a situation where she was having trouble with opening up to the thought/practice? I have never met a person in her situation who seems to be naturally ok with the state of affairs.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.