Is there some problem with setting a passphrase for recovery, beyond just the risk of forgetfulness or loss?

I'm not sure how BitLocker compares with LUKS, but the ability to set (or revoke) multiple keys in the drive header gives a lot of flexibility.

For example, The same drive could be unlocked multiple ways:

* A passphrase that you memorize or metaphorically throw in a vault somewhere.

* A key tied to the hardware so that it is automatically supplied, or requires a lesser input like a PIN.

* Same as above, but added to support another computer you anticipate swapping the drive to.