I like the new reagent pouch. I feel it can serve a few purposes aside from the obvious such as secondary gathering for irons, but the main purpose is clearly to assist in herblore.
Currently, you need to withdraw secondaries, close the bank, store the secondaries, re open the bank, grab your unfinished and then go to town.
It's not ideal but that doesn't sound too bad..
The issue is when you also pair in the prescription goggles.
You now have an additional step where filling the pouch leaves excess secondaries in your inventory (where we don't have a store all but 1 option) so we then need to either store the correct amount leaving 1 in the inventory, or storing all then withdrawing 1 alongside the unfinished potions.
The proposed update during Summer Summit with locking inventory items will likely remedy this aspect but filling from the bank on an item like this just seems like a no brainer.