I was wondering if the Expert Herbalist edge was of any benefit to a swampmaster ranger beyond the minor time reduction on gathering herbs in a swamp.

I don't need the specifics but I had hopes it would do something beyond what a swampmaster's herbs already do and I haven't seen it yet.

Bar none, for a variety of reasons.

Totally totally worth it imho.

And yes I had it with a swampdweller, and a caverndweller, and a forester.

You'll get the short timer in other terrains from time to time. The extra healing affects not so often outside the home terrain.