Doom Eternal (Ultra-Nightmare) in 12.56 seconds (Cheat%)
Channel: Undeceiver
Date: 2022-08-14

Commands are:

map game/sp/e3m4_boss/e3m4_boss - skip to last level
activateCheckpoint cp_12_boss_outro - skip to after boss is dead
ReloadMapHere - Reload Checkpoint

You can skip the last command and instead manually load checkpoint if not in Ultra-Nightmare.