How to modify includes tpl smarty template files?

I want to modify the tpl file associated with the Email widget which is located in include/SugarEmailAddress/templates/forEditView.tpl for example.

However, if you copy this file to custom/include/SugarEmailAddress/templates and modify the changes do not take effect. This is with clearing cache folder and quick repair even.

I can modify file not in custom folder and changes take effect but I would expect this is not upgrade safe!

Thanks in advance for any help.

did you find solution for that? Same problem for me.