"along the outside edge of the deck"

I think this is something you'd do after the hull/deck is all glued up before glassing the deck. Aesthetically the problem I see is that if you round over the sheer edge well this veneer will be recessed back from the sheer about 1/8"-3/16". Actually I don't see the problem with doing it except sanding the edge of the veneer carefully so you don't sand into the much softer okoume.

I'm not a fan of sharp sheers just so as to retain the look of the outer veneers matching up neatly. I don't mind sanding down into the middle veneer for a good round over letting a wavy line of exposed ply showing through. Putting a trip strip of black trip tape over it looks fine or letting it be.