completely possible, it could check for nearby bricks of the same color and see if you have a brick that would be able to fuse with it every time you planted one.
What if you make a large panel of 1X1s first, then painted your design, as opposed to having each color selected when you placed the brick?
What if someone wanted separate bricks? Like pixel artists or stained glass window for churches?
Then don't enable it... Or possibly as Dread suggested, allow the the ability to toggle it.
