Tried the Big 3 last week, and the pain in my back was worsened. Talked to the head chiropractor at a clinic where I sometimes have shifts as a CMT, he respected Mcgill as a researched, but also said that his therapeutic recommendations where off, and that he was emphasising static holds too much, and that they in his mind, especially the side plank and crunch did not have any statistically relevant effect on functional (vs. structural) back pain (quoting from memory). He did however like the SF method (when I described it) and thought 1hand swings and TGU hardstyle was if not the best, then at least in the top for what should be recommended to most clients as a prehab exercise before anything else, and he even though, that they could work as rehab exercises for many clients, provided they had proper instructions.
I went back to S&S after a 3 month hiatus, and back pain has subsided after 3 sessions...lesson learned.