Hi.
You probably could do a 5/3/1 routine. You just gotta hit the lifts more than once or twice a week and add a bunch of back off sets. If your main focus is squat, bench and deadlift something like:
Day 1:
Squat: 5/3/1 + 25/20/10 reps of back off at 75-85%
Bench variant: 20-30 reps at 65ish % of the bench TM
Deadlift variant: 15-25 reps at 70ish % of the bench TM
Day 2:
Squat variant: 15-25 reps at 70ish % of Squat TM
Bench: 5/3/1 + 25/20/10 reps of back off at 75-85%
Deadlift variant: 20-30 reps at 65ish% of deadlift
Day 3:
Squat variant: 20-30 reps at 65ish % of Squat TM
Bench variant: 15-25 reps at 70ish % of the bench TM
Deadlift: 5/3/1 + 25/20/10 reps of back off at 75-85%
Let the 5/3/1 guide your progression. By the "25/20/15" I mean 25 reps (ie. 5x5) in the 5's week at 75-78%, 20 reps (ie. 5x4, 4x5, 7x3,3x7 etc...) at 78-82% and 10 reps (5x2, 3x3 etc) at 82-85% TM. Obviously the variants of the lift willl be harder at lower intensities than their main lift so therefore the lower 65-70% stuff.
Basically the thought is that 5's week is hypertrophy week, 3's week is strength week and 5/3/1 week is a peaking week for new TM. I have no clue if this works, but hey, I'd be interested in hearing if it did. All percentages of the training max. Maybe it'll inspire you.