MightySites was unpublished from JED for a ridiculous reason: it stops Joomla from working in CLI mode. As usual - developers are notified once a listing is unpublished and now we should wait few days for re-publishing an extension :(
New version fixes this issue and master site's config is loaded in CLI now.
Configuration files were moved from site root folder to /components/com_mightysites/configuration/ folder.
New powerful features - ability to override 'File Path' and 'Image Path' settings of Media Manager (now each slave site can display own folders/images in Media Manager) + ability to override 'New User Registration Group' per site (so you can distinguish between users registered on different sites if users are shared).
New question type 'Priority List' allows you to setup a list of options which can be re-ordered by user via drag-and-drop.