Is this exploit useless?

[angry dooting]

I only have managed to reach the Antechamber once so far. Feeling very clever, I stored the key I was rewarded in the Coat Check and retrieved it the next day, but every door I tried it on got the 'the key does not fit' message. Can I actually not use the key unless I have the antechamber? Is this useless?

[Pazuzu]

The key from the antechamber opens the door beneath the elevator in the foundation.

[Pazuzu]

So just unlock the elevator this run and use the key

[bob2477]

the key from the antechamber is for the underground section that can be accessed by multiple methods each door that it should be used on that can go their has the symbol of the key on it. this key does not disappear once used in a run as it can be used on multiple doors in one run.

so the exploit is useful as it means a run where you find the coat check does not need you to get to the antechamber but means you can spend the time searching for the rooms you need to access the next section of the underground with it's puzzles and finding the specific rooms to help with those puzzles once you know what rooms you need, or what prior actions in earlier days may have unlocked.

now that you have made it once time to find and solve the next puzzle.