Adam has his scrying! He can basically communicate with different planes of reality which might be like talking to the dead, accessing areas he's not physically in—this can include minds too. This might be able to work for nightmare cradles as a way for Adam to be there without actually physically being there since he won't fight.

And if he does use his scrying, he'd ask someone to watch him so he doesn't die. But we can also let Adam die that's fine.