In the current version, the list of script templates is hard-coded in ProjectCreateScript class.
So if you want to add your own template, you will need to modify this class.

P.S. Thank you for your question. In the next version I will try to add some easy way to have custom templates.

I wrongly assumed I could just add a script template to the ScriptTemplates folder in the UltimateEditorEnhancer and have it show up in the menu of script templates when I right-click on the new script icon.

It seems that if I put a template in that folder that is alphabetically before NewBehaviourScript it becomes the default template.

How can I have my own custom script templates available in the menu when I right-click on the new script icon?

Thanks!