So, with my carbon Specialized Crux I had to make some modifications to accommodate my 11-36 cassette. This was before the x-horizon derailleur platform was available from Sram just 3 summers ago. With a mid cage x0 rear derailleur I was able to use a 34/50t chainring combo as well.
The problem with the carbon Crux was that the rear derailleur cable stop was internal. The cable exited the frame just above the dropout and was designed to feed into the rear derailleur from the rear, because that’s how road rear ders work.
My conundrum was how to route the cable housing so that it didn’t look idiotic and still worked. I fished out an old thing called a “rollamajig” made by Avid (Sram) a long time ago. They aren’t made anymore…
And Nokon housing which was purchase by Jagwire and is pretty alright stuff for this application:
It works exceptionally well. And is now paired with a 36/52t chainring combo. It is a super-competitive gravel grinder.