There is a rather old post on Forumosa here: Lesbian Hang-outs in Taipei? - #28 by rosarot
If you have any good hints, for example your 4 bars, let’s add them to that post 
Apart from that, I usually referred to these articles and posts:
https://www.reddit.com/r/taiwan/comments/498glx/best_lgbt_lesbian_areasbarsclubs_in_taipei_or/