I could imagine piles of such tools building up on the Mexican side of the wall.
There are, at least, several other ways to design climbing mechanisms that take advantage of the steel wall design.
They tested the new steel wall design with some pro climbers and the military and nobody could get over it.
-SB
Exactly why a wall you can see though is better, cause they would be seen trying to stockpile your imiginary supplies. Additionally a steel wall is stronger more durable you can fire a weapon through it and for the environmental whackos small animals won’t be impeded by it