My experience is nothing like yours.
But I can say-I would rather meet someone who wants to be my FRIEND and simply get to know me. I have NEVER dated someone who set out to date me from the onset. It doesn't work.
So instead of saying "hey I'm poly blah blah" maybe just say hey-you seem interesting and I'd like to get to know you.
Then as the relationship ensues and you get to know one another-start talking about morals, values, life goals, expectations. Poly will inevitably come up in those talks. IF you can't discuss morals, values, life goals and expectations, you can't make a relationship beyond shallow friendship work ANYWAY-so it's still working towards your goal.
That's MY two cents.
My husband and I met when I was 13. We started dating when I was 24.
My "boyfriend" and I met when I was 18. He became my lover for one day when I 20. He became my "bf" when I was 34.....
Friendship is the key to building solid relationships (imho).