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Is vanilla support any feature where the user can like/unlike the discussions?
Are "Awesome, Insightful" paid add-ons?
The reactions here are only available for the hosted solution. There is an OS alternative called YAGA. It has some issues with the current version but someone is maintaining a fork which keeps up the front end functionality. The backend would need some work.
There are several "like" plugins. You can search through the plugins here: https://open.vanillaforums.com/addon/browse/apps/recent