Legion 5 on Linux (mux / muxless) + keyboard questions

Thinking about buying one of those sweet Legion 5 with Ryzen 4800H and GTX 1660Ti.
I had a read through the big Legion 5 thread above and couldn't find any info regarding these questions.

Long time Thinkpad user, love their keyboards. Currently have an X1 carbon.
How does the keyboard feel like compared to thinkpads? Is it noticeably shallower? I'm gonna do a lot of typing on it (programming) so this is a key thing.

I'm going to use Linux on it and the plan is to disable the NVIDIA dGPU on Linux, and enable it only on a Windows VM with GPU passthrough.
Does anyone know if this laptop has a hardware mux or is mux-less? A muxed laptop will make this GPU passthrough to the VM much easier and avoid dual booting.

If I disable the dGPU on Linux, can I drive an external display over HDMI or USB-C with the AMD iGPU?

Last question - is the RAM upgradeable to 64 gb (I'm thinking yes, but Lenovo can be ***holes and lock this in the BIOS)?

 

i've never typed on an x1 carbon but the keyboards on these are excellent, i could type on this for hours.

yes, has a mux switch. you can choose hybrid or discrete.

external video ports are wired to the nvidia so no.

yes, https://www.reddit.com/r/LenovoLegion/comments/jituvy/legion_5_64gb_ram_confirmed_working/

also, the touchpad on the legion 7i and amd variants of the Legion 5 has some issues on linux, someone already made a patch for it you could probably find with a quick search