Looks like Kirigami.Sheet expects to be a child of Kirigami.Page. Thats not what we want.
I will have to talk to the Kirigami devs about that.
I talked to Marco. We will get a version that does not require a Kirigami.Page parent within a week or so.
Kirigami.OverlaySheets does not depend on Kirigami.Page anymore but still on Kirigami.ApplicaitonWindow which we don't use...
I will bring it up at the next Kirigami.Meeting
After discussion with the Kirigami people we decided that Kirigami.Overlaysheets is not the right fit for our specific usecase. We will stay with our (now reworkded) custom solution.