Responses
Unfortunately, not that much
http://www.mangago.zone/read-manga/dark_heaven/
http://www.mangago.zone/read-manga/playtime_with_hakdo/
For the ones I know
they're all here
http://www.mangago.zone/tag/seke
I now noticed that I haven't read any yaois or Yuri's where both people are switches, usually they have a specific position like power bottom or power top. This has been on my mind for a while now, I'm curious to see how many mangas/manhwas there are like this.