Its one thing to advocate one way or the other,
But there are those here who said, a Mixed Seating Wedding is Traif or they will not attend a Mixed Seating Wedding and possible insult the host.
I know plenty of very frum people who will attend a mixed seating event (They prefer seperate seating of course) but they will not insult the Baal Simcha by boycotting the event. Their only request is to sit with immediate family members and their spouses and they dont want to sit between 2 women even if the women are their Wife and Mother or 2 Daughters. or Wife and Sister .