You can save templates within X. So go to your page and at the top you'll see a button named Templates.
Click it and you'll get the option to save template as page or as a block.
If you save it as a page then when you import the template on a new page the import will delete everything on the new page you want to import too. If you import the template as a block, the import will just add the whole content of the page below the existing page content. All you then need to do is remove some sections.
There's also a 3rd option: one of the X users created a plugin called Global Blocks...which is kind of like a widget and works fine.