Congratulations again on the beautiful job. Wish my equipment pad looked so well-organized.
You have lots of good advice here. FWIW, I have a couple of
these boxes (in deep shade under big evergreens next to a fence). One for acid, the other for chlorine. Entirely plastic. Well-vented. About 12 feet apart. Working great so far, but only had them since March. We'll see how they do through the summer. (The advice about chlorine fumes causing steel to rust is 100% correct. Don't ask me how I know.)
FWIW, tabs can be useful when you need to be away from the pool for some days. If CYA is a bit low, it helps with that at the same time. It's the long term that makes trouble.