I acted in Off Off B’Way productions in the late 60s, including at Judson Church and St Mark’s Place (as well as in Regional theatres and the touring production of America Hurrah) and don’t remember men ever using our dressing rooms. But then, most of the men in these casts weren’t interested in women anyway.
Really? I’ve always seen one dressing room with men and women dressing unless it was a very nice theater. Meant nothing to anyone; they were too busy getting ready to get on stage or off at out.