Can I reencrypt LUKS master key quickly

Last time changing LUKS master key with cryptsetup-reencrypt cost several hours to finish, is there a quicker way? I think 1/3 of my partition get the new encryption is enough.

How it works. Changing keys requires decrypting from old key then re-encrypting with new one. This takes time!!!

You can not just change PW on part of an encrypted data set. All or nothing. You can, with planning, setup different sets with different keys when you install so you could target multiple setts.