Tiling Assistant basically just adds more spots to tile to, e.g; you could drag a window to the bottom of the screen and it would become horizontally tiled. As of right now, it does not work with this extension.
Correct. This extension was made to work with the minimal tiling functionality of mutter only. You can better submit a request in the Tiling Assistant project for implementing gaps.
Tiling Assistant basically just adds more spots to tile to, e.g; you could drag a window to the bottom of the screen and it would become horizontally tiled. As of right now, it does not work with this extension.