The rubber mounted "clamshell" "ragmount" (whatever ya wanna call the kit supplied POS lol) is designed for a conventional 36-spoke wheel as are most of the alternates. While you can of course make it work with more spokes and many have - it starts to get to be a nightmare.
It's far easier and in some ways better to go for a heavier gauge spoke than more of them, unless it's the fashion yer after

but remember that even the heaviest gauge spoke won't do you a bit of good if it's laced into a cheesy walmart single-wall marshmallow-alloy rim lol