Hello,
No extra content is added when using an empty template and phpdocx methods (unless you add it explicitly). We think your issue is the following: MS Word always adds an empty paragraph when an empty document is created; so if you use it as a template, the new content is added after the empty paragraph.
You can remove that empty paragraph using removeWordContent from DOCXPath. You can remove the paragraph and generate a new template without it (faster solution), or remove the paragraph each time you use it (slower solution).
Regards.