The "+" button to add blocks take up a lot of space and make the editing interface too fragmented.

Here is a starting point how it could be improved https://app.zeplin.io/project/5acc848ede054e0a4865f805?seid=5bfeb0c6d788017c627fc693

Proposal: time box and work in short collaborative iterations btw Dev & UX to find best solution.