Sorry, but I'm not exactly what you mean by 'transfer switch'. The best place to wire these in, is somewhere between the power plug on the RV and the power converter, which is the first thing the power touches.
Putting it here is what saves your bacon if there's a problem, It's the same as using a portable one. With portable, it's pedestal-portable-rv. With hard wired, it's pedestal-to and thru the plug-hard wired-rv. With the portable one my problems were 1. It's heavy. At some campgrounds the weight of the surge protector would want to pull the plug out of the pedestal. 2. It's a big investment, you'll want to cable lock it to the pedestal. And 3. The cords leading into and from the surge protector is long. Some pedestals we ran into were low to the ground, meaning the surge protecter was laying on the ground. Not exactly ideal.
I have not installed one on a Paradigm. Yet. I do have a new one in the pile of stuff we are taking with us for me to install after we pick up our 340. I'm going to say the best place is behind the basement panel that's on the entry door side of the rv. The other side (behind the Nautilus panel) is full of nautilus things. Not exactly an ideal place to put high voltage things.
Installation is simpler than it sounds. You interrupt(cut) the power line, trim back and bare the wires the specified amount(being careful to NOT cut the wires when removing the shield) and wire it up as per directions.