One time when I install it, I don’t swap back and forth in the middle of its life.Out of curiosity - how often do you have to actually adjust your headspace throughout the life of the barrel? What issues are you coming across in which you have to use this feature?
It's a bit of a double edge sword - you gain that functionality (which I'm not convinced is needed), but you also introduce a new variable that needs to be controlled (headspace) whenever you remove and attach a barrel. The former seems unnecessary and the latter seems annoying.
Barrel nuts also limit the contours available to you.
If it works for you, then who am I to say you should do something different. I just don't see the argument for needing adjustable headspace.
But I make sure it’s set up (the same as the old shouldered it just replaced) so that my old brass fits nicely vs having to deal with shorter or longer brass lengths that I could encounter with another shouldered that wasn’t exactly the same. And it’s a time penalty of like 4 minutes maybe, maybe only that long because I get another beer in the middle of it.
Barrel nuts are just another option.