Block Editor vs. classic editor is now available to all CampusPress sites. To enable on your site, go to Dashboard>Settings>Writing.
Default Editor For Users option is set to classic. If it is changed to Block Editor all new posts and pages will open the post or page editor in the Block Editor style.
Set Allow Users to Switch Editors option to yes. This provides an author to switch between the classic editor and the block editor while on a post or page editing window.
Leave the classic editor as the default with the option to switch if you have many authors used to the classic editor. On the posts and page lists you have an additional option to choose which editor to use.