Warning: ubuntu tpm recovery key cannot unlock disk outside of boot

https://lemmy.world/post/7029429

Is it still possible to add an extra key (in another slot) to unlock it with cryptsetup? Adding this extra key might beat the purpose of using the TPM but if you choose a long random key and store it in a password manager that should still be pretty safe right?
it’s not, because to to so you need to enter a valid passphrase to cryptsetup, which the recovery key is NOT