the best way to approach this loose pulley nut issue on our r*'s is to ensure its properly torqued to factory spec using loctite along with the additonal lock washer too.
Then next what do is if your a conservative rider remove pulley cover to check pulley nut status 1x yrly as a main
But if ya have mods increasing hp
/trq and ride hard/agressive with more rpm
/more vibration/more on off gas for more back & forth motion on front pulley i'd then take the extra time to chk pully nut tightness 2x yrly as a maint item.
It only takes a few mins to pull front pulley cover to check puley nut status 1x or 2x yrly,not a big deal.
I feel doing the above is a good proceedure that in most cases would help to significantly reduce the amount of loose pulleys we are seeing here in RSC every riding on.
Taking 15-30 mins yrly to do this may prevent a breakdown on the road at the very least , prevent pulley from destroying the shaft/splines on xfer case resulting in a very costly reapi which has already happened to a few peoples bikes here in RSC,or may prevent an accident should pulley/belt come completely loose/appart getting belt tangled up in the rear wheel locking it up causing an accident though that thankfully doesnt seem to be the norm when the front pulley comes loose.