Blockland can't and wont probably ever have dynamic bricks for a long time for a good reason.
The thing you call "the grid" is really "the octree"
AFAIK the octree is just for fast information storing, so when deciding which faces to use, you use the octree to determine where the brick is and what is around it. If you change the rotation of the brick... that could add hundreds even thousands of more calculations to determine face occlusion.