The first target I saw in a goose egg, I started collecting every one they laid. I never have seen a successful-appearing mating between any of my geese and the gander (no bluetooth either

). I saw lots of awkward attempts, but nothing I would call a possible success at all. Yet every single egg I have set in the incubator (and most of those the geese incubated partway) started visibly developing on around the 6-7th day. Maybe he gets nervous when he feels me watching him?

I did give them a kiddie pool. I think this is also recommended for fertility in heavier ducks, but I don't remember for certain.
Why not give yours a trial in the incubator?
Kinda funny story... I have a rooster who carried over from last winter and around 30-ish hens. I "knew" there was no way he could cover them all, and I obviously didn't know which of the eggs I collected would be fertile, so I stuffed, sans turner, as many eggs into my incubator as could possibly fit. I figured after the first week, I'd toss the clears and have plenty of room.

I think I may have had 3 clears--or 2. Don't remember for certain. There were some late quitters, but nearly every egg developed. I had to hand-turn the whole time, and I have WAY more chicks than I intended to have.
And I
hate that darned rooster! He's a sneak. Usually I'm watching but if I get distracted, he's all over me. He makes good chicks, though. Gonna make good chicken soup too, now that I have plenty of boys around again.