Not OP and not the answer you're looking for, but FWIW I own a ThinkPad Z13 Gen 1 (design is kinda similar to the X9) and literally everything works perfectly OOTB. You can even update every piece of updatable firmware from Linux (via fwupd), so there's zero reasons to have a dual-boot Windows on it, if you don't really need it.
Also the best part (for me) is that the BIOS supports Opal2 drive encryption, so you could encrypt your drive without any performance overhead and without having to muck around with LUKS. You could have multiple OSes all installed on the same drive and not have to worry about using different encryption schemes for all of them.
Oh, and all of the device driver functionality is present in the mainline kernel, so there's no need to load a special kernel/modules/drivers like most other so-called "native" Linux laptops (like System76 or Framework). What this means is that you can happily run the latest bleeding edge mainline kernel or any random custom kernel of your choice, and not have to worry about loading extra modules or repos etc. This also means that you can expect pretty much every kernel/OS upgrade to go smoothly. And that has indeed been my experience over the past couple of years that I've owned this laptop for. When you consider that not even Windows users on Surface laptops can claim a 100% bug-free OS upgrade experience, it is a pretty incredible achievement, IMO.
So for me, the ThinkPad is the definitive Linux native laptop. At least, my Z13 is.
I owned a Z13 Gen 1 and it was a horrendous piece of crap. I constantly had crashes, hangs, faulty suspend, keyboard problems, dock problems, audio problems, and so much more from the very beginning.
I very reluctantly purchased a X1 Carbon Gen 12 and am much more satisfied with the Linux implementation.
My Z13 most definitely was defective, although after seeing a few similar cases, I wonder if they had a bad batch or if that was just an unstable platform. Even after getting it serviced (which was a joke, because they don't diagnose Linux machines at the service center even though Lenovo sells them) nothing improved.
Strangely fortunate: it got stolen in Dublin and was covered by insurance.
Also the best part (for me) is that the BIOS supports Opal2 drive encryption, so you could encrypt your drive without any performance overhead and without having to muck around with LUKS. You could have multiple OSes all installed on the same drive and not have to worry about using different encryption schemes for all of them.
Oh, and all of the device driver functionality is present in the mainline kernel, so there's no need to load a special kernel/modules/drivers like most other so-called "native" Linux laptops (like System76 or Framework). What this means is that you can happily run the latest bleeding edge mainline kernel or any random custom kernel of your choice, and not have to worry about loading extra modules or repos etc. This also means that you can expect pretty much every kernel/OS upgrade to go smoothly. And that has indeed been my experience over the past couple of years that I've owned this laptop for. When you consider that not even Windows users on Surface laptops can claim a 100% bug-free OS upgrade experience, it is a pretty incredible achievement, IMO.
So for me, the ThinkPad is the definitive Linux native laptop. At least, my Z13 is.