I would never argue with "da man" Mike but I think they are scored individually, so if all goes well on a card & you master the kick you still get marked up to a max of 50 just not above. The +3 would still be there as an insentive to use kickers for most people without giving to big an advantage to the ones that prefer them.
Most of the bonous point argument on here has been about the advantage being to much when for most new shooters it probably isn't enough, if you stick a gamo compact in a new shooters hand with a bit of training & practice groups will come quite quickly. Take that same new shooter & stick a kicker in their hand & it will take a lot longer & a lot more training to get the same result.