Even my push pit and stanchions are 25mm which makes 1 inch fittings loose , I had to machine them so they closed tighter
I looked at going to a 1 inch shaft as 25mm is hard to come by, not so easy the outside of the tube would have to increase from 42mm (1.653) to 1.750 inches , then you would have to open the cutluss from 25 mm(.984) to inch which is only .016 of an inch . Then the taper on the shaft for prop is metric not SAE and theres another issue but not a biggy . Easier to pay thru the nose from Beneteau for a new shaft.
My issue was the drippless had worn grooves in shaft, was fixed by adding an R&D coupling and moving the wear back.