Magento's documentation (https://devdocs.magento.com/guides/v2.4/frontend-dev-guide/templates/template-walkthrough.html#template-customization-walkthrough) describes how to customise an existing template, by overriding it in your theme - copying the phtml from a core module into your theme then modify it.
It seems possible to add a new phtml template with a custom theme, not override an existing template. This can be achieved by creating the new phtml template in the
my_new_template.phtml was not an existing template in
Magento_Theme. Then to get that new template onto the page by using a layout file, referencing that new template and giving it a standard block, like this
<block class="Magento\Framework\View\Element\Template" name="my.new.template" template="Magento_Theme::my_new_template.phtml" />
The key bit here is that
my_new_template.phtml did not exist previously and is not being overridden. Its new.
Is this a Magento sanctioned method of adding a new template to a page from within a theme?
The [docs] I linked to at the start of this question do say
To add a new template in a theme:
Add a template in your theme directory according to the template storing convention.
Assign your template to a block in the corresponding layout file.
But there is no example and its unclear and I'm not sure I've interpreted this correctly.
Is this recommend by Magento?