Daft from your perspective maybeAlthough i imagine this approach did work, it seems somewhat daft. If you doubled the volume of the controller, you might as well just have upgraded to a larger controller to begin with, i.e. from a 6-fet to 12-fet.
From mine, with 4 kids under 7 and limited funds, it was vastly cheaper and simpler to install. Far less consumption of two resources that I have precious little of - time and money