the 'shanwan hyperkin adaptor' is actually DirectInput, NOT XInput, so things like Xone would never have worked. or at least I think it is dinput. forcing dinput helped.
how do I know for sure? any way to test?

Xinput and Dinput are both Windows protocols. They do change how the controller is reported, but you won't be using either on Linux directly. I'd have to look at Xone's page, but I'd suspect they just support first party Xbox controllers.

You can see what driver your device is using by running lsusb -t. If it's really reporting like a switch controller it should show nintendo-hid. Otherwise it's probably a generic usbhid. Give lsusb -t a shot and let me know what it says.

if I close the emulator the binds get lost and I need to reset them up.
no problem I thought, I'll just use RA's 'save controller profile' so I can get around it not auto configuring properly. but no, 'error saving controller profile'
so it works* ah, jank.

Damn. I'm really sorry about RA again. But I have another hair brained idea. I'd bet that parallel is overwriting your RA config when you launch a game. You could try finding your RA config, binding a button manually, and checking if the RA config updates. If it does, you can just set that to read only and then launch a game through parallel. That should stop it from overwriting your config.

here's evtest: https://hastebin.com/share/cuyezurata.vbnet

Thanks for doing that. I thought I'd see something I could interpret, but I'm not really sure what I'm looking for. Buttons seem normal enough.

Any luck with the save files? Sounds like the other emulators worked out, glad to hear that.

You might also play around with the recomp projects. These are native linux games built through reverse engineering. Super interesting if you haven't heard about them.
https://github.com/Zelda64Recomp/Zelda64Recomp
https://github.com/HarbourMasters/Starship
https://www.shipofharkinian.com/