Keep metadata editable on locked sales order?

[NerosKi]

Our ideal workflow is that a sales order goes to shipped and then sales can edit the metadata via a plugin to add e.g. VAT and Shipping costs for invoice generation. However when a sales order goes to shipped it locks. Would it be be a good idea to keep this field editable? I believe this is only for plugin purposes and core functionality doesn't use metadata anyway. (I am willing to do a PR for this).

[NerosKi]

In my case I have now been able to solve this directly in my plugin by creating a plugin endpoint that writes metadata directly (using UrlsMixin). I guess that might be a better approach for this more customised need.

[matmair]

that sounds reasonable