Journal templates are a useful shorthand for entering multi account entries, a prime example being paying your tax liabilities (Income tax & NI) each month. The problem is the values change from time to time (typically each tax year) meaning you have to override the values making the template far less helpful. There is no way to rectify this other than creating a new template and ending up with a graveyard of old (similarly names) templates.... when all you really want to be able to do is update the values in the template for future journal entries.
