Updated my post, thanks.

Hook changes Filter filter:user.custom_fields removed see this commit filter:user.delete deprecated, use static:user.delete instead, now It is passed { uid: uid } instead of just uid, and is fired before user data is actually deleted, so you have one last chance to look up stuff if needed. Other changes Theme developers should now explicitly set the baseTheme in their theme.json if their theme is not based on Persona. Set this value to nodebb-theme-vanilla TBD

I will tag breaking changes so that should help as well. https://community.nodebb.org/tags/breaking

I want to escape by default, to prevent accidental XSS. If you intentionally want to allow scripts then you should use double curly brackets I think its something I would rather break today than worry about it in future

Updated with header.tpl changes, relevant thread https://community.nodebb.org/topic/3488/header-tpl-changes