On a side note, a backpack like this would benefit greatly from using an object-oriented pattern, which I’ve written about on my website if you want to take your code to a more organized and workable level.
You might also consider using a Maid pattern to tear down tool buttons. I have a very straightforward, ready-to-use version in Modules. It is based on Quenty’s Maid class from Nevermore. See below:
Code: https://github.com/Ozzypig/Modules/blob/master/src/Maid.lua
Docs: Maid - Modules Documentation