I asked this question last June when I first came here on my older acc now deactivated.
I was advised not to do 531 as it doesn't allow a beginner to make the big jumps which they should make. As in 531 is for when adding 2.5kg to a lift is a big deal.... not so as a beginner.
After 6 months of 5*5 and 4 more months of other programs I have a 505/520/250 (Squat/DL/Bench)
So maybe I'd look to transferring off 531 untill the non % programs stop working.
Just my 2p