I haven't installed them yet, but my BFA gets out via his food and water doors the same way. He spends most of his time out of his cage, but for safety reasons I want to be able to secure him when I need to. Unfortunately the cage set only came with 4 locks, and his cage has 5 doors. But he usually doesn't bother with the very top 5th door. So we'll see if I need another set!
I bought my cage from the guy that invented (helped invent?) those locks, very nice guy!! AND my cage came with the locks, so I can also say from first hand that they work great - but then again, this cage is housing a sun conure so he'd probably be fine with the typical locks, but either way, the locks are nice to have.