"Judge Elayim Rubenstein had a great ruling for separate seating buses: on half of the buses the men sit in back and on half the women sit in back. He then added an important comment.
Paraphrase: Those who are very careful about certain commandments sometimes forget about the commandment to respect others."
At the kiddush we attended on Shabbat they had a strange custom, at least strange to my idea of normal. On the men's side (of the mechitza, separation) there were long rows of tables for men with chairs and tables for children without chairs. Children were reminded that they were not to sit.
On the women's side, there were round tables and no chairs at all. Women were expected to stand, and only stand, whether old or pregnant or sick.
I was a guest, but that bothered me very much. In Shiloh, a seated kiddush has chairs for both sexes. And, yes, we've developed the custom (or it has evolved) to sit separately but without a mechitza.