Impossible to hide the "request type" field in field configurations

Hello, it is currently impossible to hide the system field "request type" in JSM.
I would like to hide this field in my field configuration as I do not need it for the subtask issuetypes (sub task cannot be mapped to request type anyway so why make even this field compulsory viewable for all issuetype?).
Removing the "request type" field from the subtasks screen unfortunately does not hide it from the issue view.
This is why I would like to be able to hide it from the field configuration settings.

Thanks.