I think I know the system you refer to. My Calvert Square head I bought for my 5.2 came with nylon straps sewn into the leech end of each batton pocket and the plastic buckle on the opposing leech side. It was a great and very secure way to lock in batten tension. However, that would require me taking the sail to a sailmaker and getting all this sewn in place. Is this what you are talking about?

I'm leaning more and more towards just leaving them set permenantly - If I can sleep at night.