I wasn't happy with the positioning of the shoulder pouch on my LiteAF pack. It was (1) too high, and (2) did not close well enough to keep 500ml bottle in place.
So I opted to customise by using this stretchy water bottle pouch from Hilltop Packs. It comes in two sizes and I ordered the smaller version as I only want a smaller bottle. I also took the opportunity to use a photo from where I was standing in the Orange river between South Africa and Namibia.
My suggestion to future buyers of bespoke LiteAF packs not to invoke the option of the shoulder pouch, but rather to buy an aftermarket version. Gossamer Gear also has a good product.