There is no steam os available for general installation.
Manjaro with KDE is one of closet distros.
Holoiso exists but can be touchy. Good chance it will choke on a non and GPU. Consequence of being based on a mod of the steam deck recovery image which is only designed for steam deck.
you experience will vary.
Windows typically will erase boot loaders and install it’s own. Sometimes seemingly randomly, or on updates.
Like malware.
M$ refuses to make things like dual boot not a pain in the ass
Usually you boot into a live Linux and replace the boot loader but a dual-boot-deck 8s unknown territory to me
there are a few designed for gaming. chimeraOS is probably one of the closest, as it’s also arch iirc and I think its designed for controler, but never used it. there are a binch of them that were inspired when steamos cameo out and a few that existed before
There is no modern release of steam os. Do not 8nstall steam os 2.0, it’s a security back door at this point.
Use Ubuntu or arch vanilla or one of the gaming distros. they will handle UEFI or bios just fine.
Steamos3.0 desktop release is a long, long way away, as they have stated they will work on mobile gaming hardware compatibility first.
Likely they are finding supporting infinite configurations to be a challenge.
Ya never keep the sellers os.
Note that ‘steam machine’ is dead and there is no installable modern SteamOS for general use.
Steam machines is a name that belongs to the DOA steam os 2.0 based on debian 8, which should not be installed.