Fake-08 development trails PICO-8 so it's possible your Fake-08 version is out of date, the cart is made with a newer PICO-8 version, or the cart is just plain incompatible with Fake-08 (many carts do not work with Fake-08).
I have a couple handhelds like yours and the official raspberry pi PICO-8 build works great on them - I suggest you get a PICO-8 license and check your distribution's documentation to learn where to place the raspberry pi PICO-8 binary in the filesystem.
Just get a decent 1-2GB SD card for the 64 GB deck. Uninvasive, convenient, cheap storage upgrade with no human-noticeable performance difference between the more expensive decks.
I've owned both the 512 GB and 64 GB deck + big SD card and I can't tell the difference between them without precise performance benchmarks. The only difference is the 512 GB has an anti glare screen.
Are you using any fitness or sleep tracking apps with it? I like the design and open nature but there are hardly any quality apps I've found that integrate well with it.
Step counting is accurate enough and I go about four days between charges. Sealed version.
Aseprite I believe has a Linux build. Paid software but worth every penny.
I got the first Witcher game for free or near free with a GoG deal (after playing witcher 3), and it was very silly. I'll never be able to finish it, I don't think it aged well.
Witcher 3 is good and stands alone just fine. I suppose you could read the books if you get really into it and want more context.
My understanding is that most cheats for retro consoles are a memory location plus a value to write in that location.
I believe that's how the "game genie" worked on nes, snes, and OG game boy. Have you tried entering some game genie/game shark codes in the RA cheats for your core?
It's been a while since I used cheats on RA other than save states and rewind but I know I've gotten them working before (years ago) on snes