The boat has a dual roller system and the fit is good. Dual rollers hold the anchor in a particular attitude vs one roller around which the anchor will rotate depending on the angle of pull of the chain. In this case both the Rocna and the two Vulcans fit fine.
Attached are photos of the Vulcan 20. Both 20 and 25 is shown in the video on the bow roller, the 20 is pull tested:
Steve thought the self-launching and self-stowing action was actually an improvement on the Rocna, because of the curved shank and smooth/even motion.
We did some test pulls at low scope on sand/clay at less than 3:1 scope. (In the video we say exactly 3:1 but on reconsidering it is less, 18 m of chain with 5.2 m depth + ~1.5 m bow roller height). The anchor was setting very hard after a little skipping, and holding sufficient tension that the clutch on the capstan was slipping – even once a nylon line was added, which just stretched. The boat bow was pulled down maybe 12” or so during one back-down.
Steve had to drive the anchor out forwards with the boat, at 1:1 scope the windlass and boat would not pull it out and was risking damage to bow roller.
To grab the seabed and resist as it did, with this high angle of pull from low scope, is very impressive.