First thing I'd try which is sort of a pain physically but is cheap is change the godawful stock excuse for fork oil out and put a good quality 15 weight in there ,there are some decent Videos on how to do that on YouTube .From that point if it's still just intolerable you can try either Takegawa ($65) or Slingshot Racing ($99) Front Preload Adjusters ,or get a set of Ohlins or Kitaco front springs for $100 and pay another $100 'ish to have them installed since it takes some specialized tools . I'd really suggest the fork oil change first and try to adapt the "$15 Fork Mod" for a Grom and go from there,I have a buddy in Japan who got me the Takegawa PReload Adjusters dirt cheap and sent them to me so im going to use them but other than that my plan was fork oil change and figure out how to adapt the fork mod to a Vader .,i really don't want to end up with a 500$ front end on a $1,000 Motorcycle lol. ( Not saying I won't mind you, just saying I'm trying to avoid that lol ).
Link to Preload Adjusters here :
https://www.ebay.com/itm/Honda-Grom-...sid=m570.l1313
And link to front springs here :
https://www.ebay.com/itm/Race-Tech-7...sid=m570.l1313