Themeable site settings are now available

[Simon_Manning]

@martin

What will happen to my existing site setting changes?

If you have changed enable_welcome_banner or search_experience from the default values on your site, we will automatically migrate these values to every theme you have installed on your site, so nothing will change in the UI for your members.

What happens if I change enable_welcome_banner later, i.e. after this migration has happened? Will I need to adjust each theme accordingly?