What I do is drill and tap the hole for a 2-56 screw, screw it in from the bottom, and solder a wire to the screw. Works very well.
The hole is not pre-drilled nor pre-tapped for a 2-56 screw.🌈 FB, Yes, the CustomLine switches do have the metal frogs (why they put the black color on top is odd and I believe causes people to think they are plastic)...Not sure but it seems you're overlooking that at the side of the frog at bottom is a little circular piece which sticks out. This is meant to put a screw in to attach the (I believe, neutral) wire of the circuit. The only drilling you need is to run the wire up to the screw from below bench..🛤🌄🛤