Unless the stems are breaking, that's what repair-tabs are for. That said, I can't believe that's still the only way the slats are being hung.

Oh wait, I found a thing. I was thinking some sort of clamp would be best, and that's basically what these are.

Somehow, I doubt it keeps them from being pulled-down again, but at least you should be able to just put them back up again and again this way.