Changing target project of merge request

Latest GitLab allows to modify an existing MR in a way that switches the target branch within the target project, but it does not provide a way to switch the target project itself. This is a bit annoying, as sometimes the MR is opened against the wrong fork just by incident. Then, long conversations and approvals are collected in that MR that shall be kept for later history. Unfortunately there is no way to fix this other than closing the MR and creating a new one. That loses the discussion history and approvals. This is not nice. It would be a cool feature to switch the target project itself, so history and approvals are kept.