To increase speed on the traverses, I would optimize speed at AeT. This can be achieved two fold: increase metabolic efficiency with training around fatmax or improving VO2max in case you haven’t reached your genetic potential.
So let’s say you haven’t reached your potential of VO2max.
I would split up the prep in three cycles:
First macro cycle:
Start highly polarized, with 80% training time below AeT and rest of the training time do VO2max intervals.
Stay highly polarized, but replace VO2max intensity with Z3 workouts and muscular endurance.
Switch solely to Z1/Z2 intensity. You can keep maintenance Z3/ME workouts from time to time
This is how I would tackle it.