I wrote a post about the current/future state of Better TweetDeck. It's a bit lengthy & messy but please read it! I've been meaning to write this for a while now .
If you're in a rush, the TL;DR is: Better TweetDeck 3 won't receive any new features (only bugfixes).
And I'm hoping to ship Better TweetDeck 4 in early 2020, and it will be a "reboot"/rethinking of Better TweetDeck in terms of features.
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