I don't know if it has been done before. This variant uses two colors and can be played on any board, which should be full at the end. A point has equicolored neighbors if it has the same number of red and blue neighbors. The goal is to have more blue than red points with equicolored neighbors.
The other idea: instead of alternate turns, the builder could place for example two stones, the blocker one, and so on during the whole game. It could be used when the pattern is really difficoult. More precisely, the pattern-chooser could decide the order of the steps, like builder, builder, blocker, blocker, builder, blocker and so on (in general a sequence with length equal to the size of the board is needed, but it could be narrowed down to the following: the builder puts x stones, then the blocker y stones and so on).
Adding this additional rule a difficoult pattern can be played without filling almost the whole board as initial position.















