A quick round up of the changes in 10.4.29: Fixed some sports in WSN Forum where it was saying 'links' instead of 'topics'. Fixed an error message on adding an event when using the alertify switch. The error appeared in the alertify modal because there was a call to updateattachments() which wasn't applicable for events since events don't have attachments. Someone encountered a problem where an email notification was missing a line break, despite the line break being in the corresponding language item.
Since 10.4.27, WSN has three configuration modes. You start off in standard mode. If there are certain settings you want to change every time you take your site offline for development or debugging, you can use development mode for that. If there are certain settings you want to change when you're ready to put the site into its' mature long term ideal state, you can use production mode for that. The effects of development or production mode are defined by you, at Admin -> Settings -> Development Mode and Admin -> Settings -> Production Mode.
At long last, the new Flattern theme is available for all WSN scripts except Classifieds and Software Directory (will get to them later). There've been a lot of WSN changes involved in supporting this theme. As a bootstrap 4 theme, most of the work centered on bootstrap 4 support. It was a long slog due to the many differences between the versions, but at this point WSN can pretty seemlessly switch between bootstrap 3 and 4. There's a toggle for it on the theme settings page and also a way to specify inside the stylesheet. The templates have classes for both versions specified.
One of the legacy annoyances with WSN's bootstrap themes has been the presence of jQuery UI elements. I built certain things in jQuery UI before I made the decision to support bootstrap, and it had the advantage of working with legacy themes as well as with bootstrap themes. But with bootstrap themes, it meant you had to deal with elements that didn't obey your theme, and you had to pick a jqueryui theme that came as close as possible to your color scheme. And even if the colors match, the style of jquery ui is incongruous with bootstrap.