Newbie engraving question: Page Template changes from "page onwards"?

I am posting some newbie engrave mode questions. This lesson has my head spinning:

Page format changes (steinberg.help)
It says:

Page template changes

A change to the page template assigned to individual pages or all pages from a specific point. For example, you might have a page template for title pages that you assign to the first page in every part layout.

Pages with page template changes inherit any subsequent changes you make to the corresponding page template. They are shown with green markings in the following places:

Page template changes on the current page only: along top edge.
**> **
> Page template changes from the page onwards: along left and top edges.
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I am super confused about page template changes “from selected page forward”. I thought a page template stayed the same throughout a layout and that changing a page template applied to all pages using that template (in a given layout). This description (above) seems to imply that a single page template can look different within a layout even though it is the same template.

Can someone explain this to me? How can a page template be two different templates at once? Is there a link to the manual you can paste that explains this?

In a standard document, there are two page templates: “First” and “Default”.

“First”, unsurprisingly is used on page 1, and you can set Layout Options for it to be used for the first page of each new flow.

You can also create additional templates for other purposes, if you want.

If you make a Template Change on a given page, you are saying to Dorico: “Instead of what you normally do, I want you to use this template.”

You can define the change to apply either to the selected page, or to every page onwards.

So, I could create a new template called “Third”. And I could apply a change so that only page 43 uses it. Or all pages from 43 onwards.

Any changes I make to “Third” will be reflected on those pages.

A Page Template Change doesn’t alter a template – it changes which template the page is based on.

Ah… what you are telling me is that the manual refers to the assignment of a different page template, not that the template in question changes in style going forward. Yes, that makes perfect sense. I misunderstood the manual.