Hmm. All these years, and no-one suggested a vest with oodles of pockets as an alternative to take care of all the random, small stuff?

Notebook (paper), various types of pens, sunglasses, cabling, card reader, a bunch of SD cards, various credit card sized items (driver's license, etc.), some "quick-grab" cash, batteries, pill box, smartphone... I could go on and on what I stash in there and my cargo pants. This eradicates my need for a wallet altogether, I just need to watch out to not end up overstuffed and carrying 15kg of useless trinkets around with me.

A wise person once said that before you optimize your storage, you should strive to minimize the amount of items you plan to store.

Seriously. Don't optimize your loadout for being stranded in the middle ages through a time-travel accident. I know you want to, but resist the urge, I implore you!