I think I have worked out a way to do this, but it'd be great to have it as part of an official function of V3..
I'd like to be able to add a single product manually. Sometimes I might have a product I'd like to add to the store that isn't in the factory. So if I could add all the details in a blank form that'd be great.
..I do think I can at the moment just pick a random product though and just replace everything with custom fields - for now. I figure.. I think. Maybe.