Don't let the term "hybrid" scare you. That just means the cover is a mix of both standard solid reactive coverstock and pearlized reactive coverstock. Sanding the cover won't have any effect on the actual makeup of it or anything, it's just like any other standard reactive resin ball in that regard. Just like any other Rotogrip/Storm ball, you should have no problems tweaking the cover or even resurfacing the ball as long as you do it properly. If you want to take the ball back to its original 4000 abralon finish, sand it with 320 grit abralon, then lightly hit it with 500 abralon, and then skip directly to the 4000 pad and don't use too much pressure or time. This should restore the out of box finish. All of my Storm/Roto equipment has had tons of sanding, polishing, resanding, repolishing, etc. done, and none of them have lost their reaction.