Sometimes I make certain changes to the layout of a page using manual overrides - for whatever reason, because when I start I’m not thinking about changing the template layout, it’s just a minor local change that snowballs, or something like that - and to my knowledge the only way to turn this into a template is to edit a page template and manually recreate the changes there. When it happens it’s a PITA.
I really like the way software like Adobe Lightroom handles this - whenever you make changes to something like export settings or renaming, you can choose update the current template with current settings or save current settings as a new template. It’s a super smooth UX, where you can make per-batch overrides and later choose to include them as templates.
Hopefully it’s something that can be considered as minor feature update at some point.