Hey Tom, are you following me around the forums?
There are many ways to skin a cat and 5/3/1 is just one of them. It works very nicely, just don't expect to jump 20kg in each lift in one month.
I'm using 5/3/1 at the moment and have been experimenting with a couple of variations. Coming from O-lifting where everyone squats, pulls and puts stuff overhead 6-10 times a week I shared your concern about only doing the movements once a week so I tried doing each exercise twice a week but only maxing out one of those times.
To be honest i don't really think it helped much above the basic program.
If you really want to do each exercise twice a week plug a variation it in as an assistance exercise on another day, so for example do Back squat one day with dumbell bench press and barbell bench press with lunges another day.
The key with 5/3/1 is what i'd call "intensive" practice where as the key with a lot of other training programs is "frequent" practice.
I've been enjoying 5/3/1 because it's time efficient and since i'm super busy at the moment it's great to be able to get a whole workout including main lift, supplementary exercise and assitance work PLUS conditioning done in under an hour, 3 x a week.
Here, strictly as an example is my last week of training (this is the first week of a 5/3/1 cycle
Current 1RMs BP 130kg, DL 245kg, BSQ 200kg, MP 85kg
Cleans 90kg x3 100kg 3x3
Bench Press 90kg x5 100kg x5 110kgx7 (rep PR)
Back ext 3x8 20kg
KB situp 32 kg 3 x 3/3
Run 2:00 / 1:00 @ 12, 12.5 and 13km/hr
Deadlift 170kg x5 185kgx5 205kgx5 (rep PR)
Mil press 50x5, 57x5, 65x6
Glute ham raise 3x8
Kroc Rows 3 x 8/8 48kg
Rowing - tabatas 4:00
Squat 130 x5 150x5 170x5 (rep PR)
pullups 5 x 8
Plank 3 x 45 seconds + 50kg
KB windmill 3 x 5/5 24kg
KB snatch 3:00 / 2:00 x3 24kg
AS you can see my assistance work centers around core strength and stability at the moment because it's my weak point.