Andrew, I had a similar issue on my D380GL. I contacted Lewmar for advice who said that the usual hammered pin chain link plate would run through the windlass so I could add my extra 25m to give me 55m of chain and 30m of rode. I really like octoplait and have a length of it as a bridle snubber but i wouldn't want it as part of the anchor set-up for the reasons you've observed. Lewmar themselves commented that the gypsy is more than happy to run a combo of chain and rode….and has done so for me. You could consider replacing the octoplait with a much longer length of standard rode [mine is14mm methinks] once you know your windlass gypsy will haul it in and switch to chain without jamming. Cheaper and much lighter! One of the guys on here has removed his chain completely relying solely on [a lot!] of rode and has used it very successfully in tricky places for many years in the Scottish/Western Isles area.
The membership association for owners of Dufour Yachts