There's no big reason why remapping couldn't be done in a way that doesn't require actively running software on the host machine. QMK, the open source firmware for keyboards has had this for years. You can update your keymap with an online editor, but once it's flashed, your mappings will be remembered regardless of which computer/phone/whatever you use the keyboard with - without having to run any software besides the OS on the host.

The K6 is not programmable out-of-the-box, but it seems some people have successfully installed QMK firmware on it (with caveats); https://github.com/CanUnesi/QMK-on-K6/

If you just want to try the numpad thing out, it might be easier to use something like AutoHotKey. Here's an example of a script that uses CapsLock to toggle the numpad layer.

Of course, AHK scripts only work with the computer you've installed them to, whereas using programmable firmware will work regardless of which device you connect your keyboard to.

Huh.. Do you also move the cursor with your keyboard? And if so, don't you have an RMB key? If you don't use a mouse, do you use a GUI that isn't suited for keyboard navigation?

There's plenty to do if you install mods, particularly Modular Encounters Systems. Also, check out Splitsie's Survival Impossible -series if you need more inspiration :)

The responses read like they were generated with a large language model. Not that training such a model wouldn't take a bunch of time, but at least then the effort would approach zero over time.

Yup. Just a few kelvins.

IMO Steam Deck is the best overall option, as it's beefy enough to run PS3 or even Switch games.

If it's too heavy, the Retroid Pocket 3+ is a decent emulation competitor with a lighter, smaller form factor.

I find myself constantly switching between them all and can’t settle down to actually play a game.

This sounds like one of those problems where buying more hardware doesn't help. Ruminating about the "best" handheld choice is an easy way to forget about playing the games themselves. I've been there. The solution is to just pick a device at random, and go outside to play it. There will be pros and cons, but if you're not even getting to the point where you can actually play the game, then the pros and cons don't matter either.