I don't remember saying that since my method utilize ONE main lift per session. I said that you can use it for more than one lift during the week.
I'm not someone who recommends assistance work, but if you do it you do it at the end of a session.
My sessions are like this:
Loaded jumps or jumps
Main lift for strength (this is where the wave ladder can be used)
Main lift for density (e.g. 80% of 1RM for as many total reps as possible in 5, 8 or 10 minutes)
I have other methods, but they all involve focusing on one main lift per workout and using minimal, if any assistance work.