Hi magpie,
I’m not so sure I would frame this as a better or worse choice as much as a personal preference because there are pros and cons to both sides. There is more about the pros and cons of wool quilting in post #6 here.
Almost all 100% natural Dunlop would come from overseas (the only North American source would be the continuous pour Dunlop that is made by Mountaintop foam) but a shipment only has to be fumigated if it’s shipped on untreated wooden pallets and I doubt that any experienced importer would be foolish enough to use them (see post #2 here).
Phoenix