One problem with chasing engagement metrics is they simply can’t rise forever.
At some point it levels off. And then what?
Worse yet, engagement comes at a cost of satisfaction.
Are any of us more satisfied using any of the major social media tools these days?
Combine any engagement target with a satisfaction or relevancy goal. Use surveys or pop-up polls if you like. There’s no point in having a more engaged community if it’s a less happy and satisfied community.