The project page states:
More block positions and up to 3 column main content. So you can have left and right sidebars blocks inside your content page.
Is it possible that this feature has been removed in the D8 version? Looking at the code it seems this configuration option is not available. If so, please update the project page.
Needs work
1.0
User interface
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.