Those studs are only going a little over half way through the lug from the looks of it. That may be a problem down the road and there are heavy cantilever forces on those studs with spacers...but they are 12mm so may not be an issue. Measure both the CFM stud and the studs on the spacers. They should be the same. If not you might want to replace yours with longer ones....someday.
Just FYI, CFM cheats on stud length because their wheels are thinner and don't need the standard length. I discovered this when I swapped wheels and tires with my Brute. I couldn't use the standard closed lug as it would bottom-out on the stud before getting tight on the wheel. Had to use the old open top lugs. Measured both and the CFM studs were 6+-mms shorter then what was on the Kawasaki.