I was able to complete most of Square B-1 by following the directions. The one change I made was as follows:

Round 8: Attach new color of yarn in any 3-chain corner and ch-3 (counts as first dc), dc, ch3, 2dc,* [skip next sc, and make 2dc in next sc], repeat from [ to ] seven times more, (2dc, ch3 2dc) in next ch-3 space, repeat from * 2 times more, [skip next sc, and make 2dc in next sc], repeat from [ to ] seven times more. Join with sl st to first dc made.

From there, I was able to work Round 9 as described in the directions.

Here is what I am up with: