if its anything like the original ally you can just directly boot into the bios, dont even touch windows and i think its very unlikely that they will manage to remotely update your firmware forcefully if you already put linux on it unlike the switch or ps5 where you have to buy the first edition of it in hope of jailbreaking it years later

the whole microsoft has their own silicon on the APU die is true for the original and yet on mine running bazzite i don’t think they’ve got any control over my unit

Its in the same menu

In terms of external displays i believe you wont have a problem with them considering on the x you could hook up a (standard usb 4) egpu and even on the non x with a dock you can get a 4k60 display (depending on the dock and maybe even freesync) I don’t think the cpu performance is the limit (it performs on par with a i9 4 generations behind but with 30W), nor the ram (windows paging is what makes win11 usable on that when gaming), although battery life on my z1e ally (non x) is awful but when plugged in that won’t matter. What I am concerned about is longevity of the hardware, its not like a standard laptop where the ram is socketed, the wifi card is socketrd (which I HATE, please do put that in mind this is a mediatek wifi card which isn’t replacable and has latencies that spike so bad for absolutely no reason and it makes remote desktop unbearable) although you can always plug in a usb to ethernet NIC on that hyptothetical dock youd be using it on

The amount of memory that is dedicated to the iGPU can be changed (at least on the normal ally non x) It’s a range from basically none (auto) to 8GB on my normal ally