I like the product (the wider version), but found it very awkward to install. There simply is not enough room in the box for all the wires. Also, the amount of stripped wire that you install in the slots seems very short - possibly unsafe. Also, the holes to feed cables in are too narrow - cannot accommodate even two NMD90 cables (with sheath). Rather adopt standard North American box sizes and fittings.
For my project I actually needed two lines (power sources) and one load (output). In fact, I cannot think of a 20 Amp application where you would need a switch with two live wires in and two out.