Rear Leaf Pack Shims - How Important?

So I installed an AAL this afternoon, and on the second side, after I went to put my tire back on, I saw one of those metal shims that sits between each of the factory leaves on my driveway. I was exhausted, and just put my tire back on, shaking my head in disbelief. My question is, how much of a priority should the replacement of this metal shim be for me? Do I need it back in place before driving my truck again? Will I be on for a week? A month? A year? Lol. I really don’t want to take that leaf pack apart again…

 

I think they are for sound, if it starts squeaking, hose it down with fluid film. If it bothers you enough then pull it apart and redo. If it was me, I would probably just leave it for now and see what happens.