Update: As it turns out, there are Switch-specific upgrades for this port. In a separate post on the Campo Santo blog, writer/designer Jake Rodkin explains:
"We’ve been hard at work stripping much of Firewatch’s tech down to the studs and rebuilding it to render the world more quickly, to stream and load faster, and to generally be more responsive."
He adds that those optimisations should hopefully be rolled out to other versions of the game after the Switch release.
"Plus," Rodkin adds, "we’re hoping to throw in a couple surprises just for the Switch release."