BSPS sells the ratchet kit now.
https://benstoegerproshop.com/competition-belt-ratchet-kit/
I've attached them to my standard DAA belt. It's hard to explain but here's my method to prevent bunching on my inner velcro belt - when I put the outer belt on, I start ratcheting it down and when inner velcro might start bunching up I separate it it with my fingers until its tight enough, then l let the velcro attach. It might be more helpful to have a card or something separating the velcro so it can slide (instead of bunch) while you tighten the outside belt. But using just my fingers works for me.