Support Ticket Departments Custom Fields

I have quite a few custom fields I need to setup for each ticket. I am finding it impossible to do this because when I click the custom field tab and add a field I have to save it,which saves the department and then i have to open the department back up, go back to custom fields where i am able to add the next field and then save once again only to have to keep opening the department each time to add another custom field.

Another issue with this is I have to first create the department, save it and reopen it before the custom field tab is even visible to use.

Why is there not an add button to keep adding custom fields until i am done?