Being someone who has used switch rods in the salt, I will throw my experience in the pot.
Leave the switch at home when on the rocks, simples. They may be perfect on the beach when you are wanting to put a fly past the last breaker, but when it comes to stopping a fish going deep, the shorter rods have the advantage.
My setup is a Helios 7 weight Switch teamed up with a 9 weight Rio Outbound for over head casting, as recommended on the Rio site. Putting the whole line out is easy, no question there, but as soon as you hook something the impracticality of a long rod on a cliff edge comes into play.
Nope, I will stick with 9 footers from 7 to 9 weight thank you very much. More command, more stopping and lifting power and easier to grab your line to pull fish up the cliff. Besides, the fish are normally within 5 feet of the rock face, no need for long casts, cast along the rocks, not out to sea and you will have plenty of good fish.
PS. Also used the switch for Pike, back to 9 footers, as are everyone else that have written about using Switch rods for pike