Ray,
I am sorry, currently we do not have provision to create new JSP using custom templates. Custom templates can be used in JSPs. To add custom templates to your JSP, type “<” and press [Ctrl] and [Enter] key, this will show the content-assist with the list of custom templates.
I will raise a PR for the dev team to add provision to create custom templates to be used for creating new JSP pages.
Sorry for the inconvenience.