Paul Haddad and Mark Jardine - Tapbots - have posted a frequently asked questions (FAQ) page dedicated to Tweetbots 3, and more specifically, any common confusion or feature requests people might have. From Tapbots:

Why did you get rid of double/triple tap?

In order to detect a double/triple tap every tap on a Tweet adds a delay while the OS decides if you are doing a single or multiple tap. This lag really impacts the feel of the app in a subtle way. There’s some ways around this but it ends up causing other issues. We understand some of you really miss this feature and are discussing how to best handle it.

Lots of other good stuff there, including the Night Theme, additional swipe gestures, custom text size, new List behavior, and more. Check it out, and let me know if it answers your questions?

Source: Tapbots