I can help you only a little. On the M1000's evidentally the reflash that they had put the '09 code in them so I believe it was basically as simple as then removing your reverse stuff, rewiring from the reverse button to a certain pin on the ecu and it would work. There may have been oil pump mods needed too which i'm guessing is what the kits that were being sold involved. I would guess if one only used reverse for short amounts of time that unless it would damage the oil pump by spinning backwards, that could likely be skipped without any harm?
If, and this where I don't know, you could get the '09 800 code put into a '08 ecu then likely the same can be done. Since nobody that I have seen or heard has done this, my guess is for whatever reason the '09 code cannot get put in an '08 ecu. You would then have to buy an '09 ecu and then the cost would go way up.