
Just:
- copy Your active template with another name
- MOVE Your plugin/module tag from page content to template - at location above or after {content} tag - yes, it is kind of limitation if You use some table-design in Your page content
- edit Your content page properties so it will use this new template.
RESULT:
User can delete anything he want (in page content), but Your module will be still here

It is only small thing, but I hope it will be usefull for someone else also.