Jim
Been doing 5/3/1 for almost 4 years now, so have a fair amount of experience. I saw in a couple of posts where people combined fsl and bbb your recommendation not to. What I found is that if I do the bbb on the oppositie lift (ie deadlift when I 5/3/1 on squat) it actually works really well. I just finished a 9 week cycle and tested my previous maxes and frankly they moved super quick which I attribute to the volume. Take it fwiw since I know everyone is different