There's another concept that might fit well for a lot of people -- that of the "Read Me". Most software comes with a "Read Me" text file that explains what you're dealing with and how to use it. Similar to an instruction manual that might come with an appliance. The idea of doing a "Read Me" for yourself is to explain to potential lovers/partners what they're getting into when they get involved with you. Your needs, triggers, hard and soft limits, other relational boundaries and communication patterns, likes/dislikes, etc. I haven't done one myself yet, but I've read those of a few other people, and I love the concept.
The Secondary's Bill of Rights was created, as far as I can tell, to draw attention to the way that people in secondary-type relationships with people who have another, primary-type relationship, often seem to be treated as disposable or less-than. You could call it a tool to remind all involved that a person needs to be treated like they're of value, even if they're not a life-partner... which SHOULD be obvious, but which doesn't seem to be, based on a lot of stories you read on boards like these.
I'm not sure whether the same problem exists in reverse... whether people in primary relationships get treated as less-than by the people with whom they're in secondary relationships on a regular basis. There's a power differential there, y'know? But then, I have an unavoidably biased perspective, being a practitioner of solo-poly myself. Still, what I'm saying is that a Secondary's Bill of Rights as a way to draw attention to a set of problematic patterns in poly makes sense to me. I'm not so sure that a Primary's Bill of Rights does. A "Read Me", on the other hand, is probably a good idea for most people.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.