Update, did the 3.3 to 3.4 update, it did indeed remove SteamOS from the boot manager. Booted to SteamOS via file (vol up + power, boot from file, esp/efi/steamos/steamcl.efi), opened konsole then did the command below:
Code:
sudo efibootmgr -c -L "SteamOS" -l "\EFI\steamos\steamcl.efi" -d /dev/nvme0n1p1
Now I can boot normally back to SteamOS. The Windows entry was untouched so didn't have to do anything with that.
Edit: Looks like it may have updated the display firmware, I lost my custom refresh rates in Windows so I had to load them up again with CRU. Also noticed the windows 11 touch keyboard is now the correct size.