It actually uses the sorted order of the folder.
So if you change the order of the content in the folder to manual you can control this as you like today
It’s on that page under the heading “Customizing content”
More than one page template can support the same content type. In this situation, the template that appears first in the Templates folder will be used to render the content by default. But individual content can be manually configured to use any template that supports its type. For example, in the image below there is a content type called “Post” and two templates that support the Post type, first is “Post show - 2 columns” and then “Post show - 1 column”. The “Post show - 2 columns” will be used automatically by all Post content. To force an individual Post content to use the 1 column template, edit the content and select the 1 column template in the Page Template dropdown at the top of the Inspect panel.