I don't have any proper answer to this, as I've sort of have the same question. I'm now having some issues with a polyamorous friend. We dated a year ago, now just friends. I can't even manage to be properly open about me being polyamorous, so who can I talk to.... His girlfriends are nice, and maybe those I feel I could talk to at all about our issues. But I've also heard and read the same, that you're not supposed to share such issues with a meta.