Of course the only rules that count are the ones that work for you & your loved ones in your relationships.
That said, speaking as someone who has been involved in poly relationships, and power-exchange bdsm relationships for over a decade, I can say for sure (for myself) that healthy poly has to involve people consensually deciding what is right for themselves.
I have seen power-exchange based poly relationships go boom because some master/mistress ordered their slave/property to do something that was against that person's poly or mono nature, whether it was have no other relationships, or to have a relationship that they didn't really want.
Feelings cannot be dominated. It's like trying to whip the stormy seas into submission with a cat-o-nine tails.