@Gallium The lower high flags are 32" off the ground. To reach that height you'll be very close to breaking the horizontal expansion rule, if as you say, this tipping wouldn't break the vertical expansion rule. Your third dimension can only be about 16" before you'll break the 36" expansion rule. You can't physically block the tallest row of flags.
You can NOT tip, using a part of the robot pushing against the floor, in such a way that any part of your robot is more that 18" high outside of the expansion zone. For example, if I have an 17.5" tall robot and I extend legs down that lift a corner of my robot (tilting it), as soon as any part of my robot becomes taller that 18" as measured from the surface that the robot is on, I am now in violation. If I had a 32" wide and 5" tall robot and tilted it in the manner above, as soon as any part of the robot becomes greater than 18" tall, measured from the surface that the robot is on, then I am in violation. In these two cases, the robot is itself expanding beyond the 18" height limit outside the expansion zone.
The only legal way to have part of your robot more that 18" above the floor tiles outside the expansion zone is to be on a platform, in which case your robot height is measured from the surface of the platform or if your robot has driven onto a field or game element, causing it to tilt in such a way that a part of the robot is now more than 18" above the floor. In either of the above cases, the robot itself did not expand beyond 18", it is merely the position that the unexpanded robot is in.
To me the best way to think of it is as follows: when the robot was inspected, it had to be inspected in the position that you would place it on the field at the start of the match. That then defines the plane that the robot sits on. Outside of the expansion zone, a robot cannot extend above 18" above that defined plane. so in driving up onto a platform, it is expected that a corner of the robot might be greater than 18" above the floor.