Can’t change passphrase on encrypted core storage device

I can no longer change the encryption password for external (spinning disk) core storage volumes. The File → Change Password… menu item in DiskUtil seems permanently greyed out. The diskutil command no longer has a verb to change passwords for core storage devices (only for APFS). It used to be that diskutil cs passed <uuid> did the job, but no more.

The only possible way I’ve found is to decrypt and then re-encrypt the entire volume. That is done by right clicking on the volume in the left-hand pane of a Finder window (doesn’t work on the desktop). But, that takes hours and is therefore not a real, viable solution.

Anyone have any ideas?

I’m running Big Sur 11.6.2.