Good to hear how you’ve approached this job. As a temporary measure, I’ve scrapped off the surface sealant which had cracked & dried, & then applied new sealant on top. Neither of my hull windows appeared to be in danger of actually separating from the hull, so this was probably more of a cosmetic temporary measure than anything else. Will probably do the job properly next year.
Do let us know if you here anything from Dufour.