Update #3 & Negative Scores...

[JTH]

Two things:
1 - In the scenario as described, base score blue is zero, as the crate held by the robot as the multiplier stack is counted as zero points.
2 - Assuming there was another box still in the scoring zone, that one box would be counted as one point. It's not (B-X) anymore, as the equations have been showing, when you have an opponent supported stack. It's one point for every crate "in" the scoring zone that isn't in the highest stack.