You need a way to deliver the warhead perpendicular to armour plate of the tank with sufficient force to disable the various safeties. If you don't accomplish a

You need a way to deliver the warhead perpendicular to armour plate of the tank with sufficient force to disable the various safeties. If you don't accomplish all those things then the shaped charge will do virtually nothing to the armour plate. As far as I know it's difficult to 3D print 88mm cannons.