I have a Clevo NV41MZ, which is sold by Novacustom and they, together with 3mdeb develop Coreboot for the Clevo Laptops.
Its pretty great as their Distribution (Dasharo) as well as Heads run on it, I guess theirs is better optimized and it looks secure and feature complete.
So very great laptop, also did a Benchmark against my T495 and was shocked about literally twice the performance! Its pretty loud but Dasharo actually fixes that.
Keyboard problem
So... bad part, the keyboard.
Its crap, not unusable, but my T495 is the best Keyboard I ever used. Lower travel than on my (also corebootable) T430, nice rubbery keys etc.
Interesting though, you cant replace the keycaps, while you can on the Clevo boards.
Also Novacustom sells the Clevo keyboards and you can get custom engraving, layout, font, everything, you can literally design your own keyboard, its pretty damn cool.
But... they keyboard is still a huge deal, and as I only want to have one Laptop (lol you wish) it should be good for writing Bachelor thesis stuff on it.
Keyboard to USB
There is a like 10 years old video of some guy hacking such an internal keyboard to USB, sniffing the keypresses and all.
The easy solution here would be to get a USB Thinkpad keyboard and disassemble it, but its costy and not sure about the quality and compact laptop size.
Keyboard 1 to Keyboard 2
So I imagine it pretty badly, two proprietary connectors talking gibberish and very differently, and you need to solder two random ebay parts together and hope it doesnt need translation.
I imagine you could remove the need for the arduino, as it doesnt need USB.
Maybe the OS could handle the keyboard layout changes?
Is this possible? I imagine getting a T495 keyboard and putting it in my NV41MZ, needs some cutting but should work?
You could ssh to your clevo from your thinkpad, or get a bluetooth keyboard, the keychron or royal kludge are great and can be had for under a 100, or you could desolder the keys on the clevo and replace them with scissor switches like in this article https://www.tomshardware.com/news/kailh-laptop-switches-scissor-light-pipe,34652.html
Hahah the point is that my Thinkpad is not trustworthy as the firmware is garbage and not updated since forever. Like, this is a security nightmare?
Interesting project, but desoldering keys? That sounds like a hell of pain...