Mograph shader - transforms bevel

Dear all!

I have a cube with a fillet of 2cm with 3 subdivisions.

This cube is in a cloner object with a mograph shader effector applied to it.
The effector animates the size of the cubes on the y-axis. Buuuuut this effect also transforms the height of the fillet.

i would like to keep my 2 cm fillet no matter what size the cubes become

any ideas?