There’s two models - the Duet 3 which comes with a Snapdragon 7c Gen 2 @ 2.55 GHz CPU, and the 3i which comes with a Intel Celeron N4020. I would rather use the Duet 3, due to the cover, and since I am already familiar with the feel of the device due to having owned a Surface Pro 4, but I’d like to choose whichever works best for running Linux.
Edit: Just for additional information I’ll be using it as a note-taking tablet with xournal++, not for any heavy tasks
Chromebooks use a customized Linux kernel with often proprietary code included from the manufacturer. Same thing as Android in that sense.
Upstream Linux, using mostly open-source code, does not have these bits of proprietary code in most cases. This means that ARM devices are frequently missing some drivers under mainline Linux, so things like TouchPad, wifi, or even GPU might be partially or fully unsupported.
Armbian Linux supports a large number of devices using mainline Linux with some tweaks to it pre-configured, but typically you’re not going to get every feature of the hardware supported until several years after its release (like 5+).
x86 on the other hand usually will just work out of the box, especially Lenovo laptops.