May I ask what you carry in one key pouch? Cards, coins, cash and keys?
Usually ID, cards and cash in the flap pocket with coins in the zipped compartment. I don’t use that for keys as they are kept separately in the canvas Key Pouch. However, there’s a key hook in the Empreinte Key Pouch that I don’t usually use so yes, if the key hook is used then all the items you mention fit in there.
I like carrying two Empreinte Key Pouches for traveling as one for home currency with a spare credit card and the other local currency with credit card. I’ll keep small amounts of local currency for purchasing small items.