Good subject matter. My two cents worth... I have been married for 38 years, poly as long as I can remember. Active poly the past 20 years. We are honest with each other and those we bring into relationships but we choose to keep it withing our personal circle. We are and will remain in the closet because; 1) it is our personal choice much like our spirituality it is ours. We have an inclusive accepting nature we employ in our every day busy life. 2) Respect the personal views of others. Some of our friends, family and colleagues would not understand and could be conflicted by our choices.
While we don't promote our choices openly we do offer our perspective and experience to anyone who asks. Example: A friend recently asked what our secret was for keeping our marriage fresh. I could tell she was searching for help with her stagnant marriage. I first wanted to confirm that my experience would do no harm. I asked about her marriage and was satisfied that she was in a strong stable marriage. So I told her of the great freedom, passion and warned her of the NRE (New Relationship Energy) etc.
Love grows even more when unfettered.