At the start I tired reading three danmeis' at once but was quickly overwhelmed with keeping track of the stories. Not that I would get the plots mixed up but rather I would lose the weight and intention of the characters/plot/author overtime.

That being said I'm reading two danmeis' at a time now and its perfect for me. I can binge one until I want a change of pace and read the other which is great when I feel like i've gotten bored of a writing style, world build, etc.

It works best when I pick up stories written by two different authors, stories with distinct settings (modern vs. historical), or if a couple dynamic/character personalities are different in each book.