I’d say 3x a week as well. You’ll stay pretty high up on fresh and if more people are liking, commenting more frequently you’ll get up there on trending. I update 3-4 times a week, depending how the days fall. Interacting with other creators in the forums and under their stories is a good way to up your subs. I read and comment frequently on the stories I’m caught up on and some of their readers have checked out my story and subbed.
Being interactive in the forums is helpful too. Even if it’s not a topic where you share, someone can still check your story out if you have your link in your bio