@Timer: Will change art asap
@XYTWO: The side which the additional block spawns on could theoretically be on any side as the end result would be the same, but as for user preferences I think people would prefer having it spawn to the right of the selected block.
As for the end blocks, force field will only be able to affect 2 blocks, no more and no less. So if you targeting the far right blocks would affect the block directly to the left of it (as opposed to spawning to the right in other scenarios).