Exactly what does flashing an outboard involve? Just having something re-program the ECU? Or is there more to it than that?

How much does it cost?

If you bought a boat rated for 225 HP max, which would be cheaper: buying a 225 SHO or buying a 200 SHO and having it flashed (to 231HP is what I have been seeing on the forum)?

I think those two motors are built on the same block, so I think they would weigh the same. Correct? So no gain in performance from a weight loss because there wouldn't be any.