Hey this game is broken and it's great.
Niiiiiiiice. You're playing it exactly right! It's hard to break the Dots & Boxes habit of making lot of small rooms, but in reality even just a few big room REALLY rack up the points! Small rooms work much better as a way to BLOCK folks from making larger shapes. It's been fun watching the game teach people how to take advantage of the scoring system in real time, and it almost always leads to dungeons that start as a lot of small passages before opening up into larger rooms deeper in (which makes sense from a layout perspective!)
We also realised that you could do a map for a wizard's tower by restricting the play area to the dimensions of the previous game, and putting the S in that space so it matches the last game's F. It was pretty fun!