Take a look at a few of the themes that already do something similar Dave - for example you may actually be needing to override the renderer in Boost as the core one may already have been overridden, depending on your parent theme
There are many examples in existing themes, such as https://gitlab.com/ro-mdl-themes/moodle-theme_handlebar/blob/master/classes/output/core_renderer.php and you'd certainly also find examples in some of Gareth's themes like Essential or Shoelace and in Adaptable or Moove and others I'm sure
Hope that helps.
There are many examples in existing themes, such as https://gitlab.com/ro-mdl-themes/moodle-theme_handlebar/blob/master/classes/output/core_renderer.php and you'd certainly also find examples in some of Gareth's themes like Essential or Shoelace and in Adaptable or Moove and others I'm sure
Hope that helps.