The reality is that there is really not much difference between a switch and a spey rod, especially for switch rods above a 6wt. You'd have to have popeye arms to cast an 11ft 8wt switch all day long overhead. I mean it's possible, and while I could
cast my 12'6" 7/8 spey single handed with a light scandi head, I'm not crazy or strong enough to do that for a day of fishing.
So while the intention of the switch rod is being able to go between single handed over head casting and two handed water anchored casts, perhaps one quality often overlooked, but much more practical, is that almost any switch rod can perform fly casts of various kinds, and then be "switched" to perform admirably with a center pin reel and a float should one desire.
I've not made that "switch", but it's intriguing, especially when fishing very small water where a 30ft cast would put you 10ft into the bushes on the other side.
Nowadays, perhaps the best etymological link for the word "switch" when referring to what is essentially a short spey rod is to the word switch, meaning a short stick
Other than that, in rod weights appropriate for PNW and BC steelheading, they really are simply short spey rods (which shine with scandi and skagit heads). Cast it however you like.
A buddy of mine refuses to learn spey casts and uses his 12'6" TFO
single handed all day long with a 340 AFS. I keep trying to get him to learn, but he's not into it... to each their own.