ssartjb Does the latest Buildr by default use the update CSS Grid code for layouts so that the templates are Joomla 4 ready?
You may kindly refer to forum post here being quoted also thereafter :
We’re in progress of updating templates to be compatible with Joomla 4. For the Bootstrap 4, there would be new framework, new templates for new version of Joomla.
Also, You may kindly view this blog post and here to know what's new with Joomla 4
You may always view the Release updates and related blog posts from time to time, through here for which Mail Notification alerts are also sent to Premium members whenever new blog topic is posted 🙂
Hope this helps