Is there any OS that allows this config?

At least with Linux, if I encrypt my hard drive, I have to enter my encryption password on every login, for some even during boot.

Not sure about Windows. I wpuldn’t be surprised if you can have bitdefender on with auto login.

From memory yes but the contents of your home directory are inaccessible until you enter your password via a popup. For whole drive encryption probably not.

I had configured this manually (incorrectly) in Arch a while back to have my home dir be on a separate encrypted drive.

Turns out the main drive didn’t get the memo and still had a home folder which worked fine, I thought it was working so I promptly forgot about it. Meanwhile the encrypted drive (which had only ever been unlocked that day and never again) had maybe 10 files on it? That I didn’t even know it had until I swaoped the drive into a different PC.