To me, the short wheelbase creates a situation where rack is rather far behind the bike's center of gravity. Way back there. This pic doesn't have panniers, but I can imagine a situation where you get loaded panniers too far behind the rest of the bike, and that is what contributed to the waggles I experienced when loaded touring on the Troll.
I am curious to check out the proportions of the frame/rack/panniers on Seafoam to see whether the mass sits a little closer to the bike's center. I think the Troll is a great multi-purpose bikepacking bike. For me, it just didn't work out as a loaded tourer.