It was observed that the vault owner can transfer the ownership to address(0), which effectively burn the ownership.
https://github.com/code-423n4/2022-07-fractional/blob/8f2697ae727c60c93ea47276f8fa128369abfe51/src/Vault.sol#L93
It is recommended to implement a validation check to ensure that the ownership is not transferred to address(0).
