Louie Simmons is a big proponent of mini-sessions in between major workouts. These usually focus on weak points and GPP. They're usually around 20 minutes and you're recovered from them by the same time the next day.
This could be like tire flipping with some band triceps extensions and face pulls. There's a zillion other things you can do too.
This is a concept that can be applied to most programs. I remember when I lifted at a college PL gym, the strongest guys were the ones who did work outside the gym too.
We did 3 workouts at the PL gym a week. Monday was squat focused, Wednesday was bench Focused, and Friday was Deadlift focused always doing the PL movement itself.
A lot of guys trained in the open fitness/recreation center on Saturdays to focus on shoulders, back, and triceps or do extra work for the squat. Even in between those days, I frequently saw them doing cable triceps extensions, glute/ham pullthroughs, and upper back work.
I just mention this if the reason you want 6 days a week is because you're one of those people who has to move around some nearly every day to feel right. There certainly wouldn't be anything wrong with doing something totally unrelated like jogging, bikecycling, kayaking, a light short session of climbing, or whatever the hell floats your boat either so long as you don't push it so hard you can't do your PL sessions well. Malanichev actually likes to include running in his program.