I've got a couple Win10 systems that can't into Win11, both mine and friends/family. A couple questions going forward:

I like how they are currently configured/tweaked/installed software/etc. Also, they are all legit, activated licenses registered to microsoft accounts. If I massgrave into ENT editions to get muh Three Moar Years, what will I potentially lose? Will settings get changed, features deleted, license registrations revoked, other Bad Shit ..? What should I prepare for &/or look out for after converting to ENT? What happens if I refresh a system and ask it to bare metal reinstall? Would it be better to save & migrate current settings instead of a complete nuke?

Also, I've seen mention that legit user licenses are eligible for one year of free security updates. Any idea how to get this? It seems to be a myth, or microsoft has buried it under bullshit.

I intend to IoT LTSC install from scratch on systems that I can, but some systems that is not a good solution for several reasons. If I bare metal an IoT LTSC, will those systems still be eligible to register/activate for personal microsoft accounts? Especially if those accounts are currently tethered to other Win10 editions? Does microsoft track or care about this shit? Would I need to go into the accounts and remove previously registered devices?