Do the collars or springs void any part of the factory warranty?
Technically it could. You're modifying ride height, which changes your CV angles, modifies your shocks, etc.
That said, I had my CV boot replaced under warranty with RPG collars installed and the dealer never even asked about them. It would ultimately depend on your dealer.
Not sure what year your truck is, but if you have a 2019 or 2020, we've successfully run the VenomRex wheels (20x9 +12 offset) on 35x12.50R20 tires with no collar, no springs, and no rubbing. The 2017-18 trucks ride a bit lower so they'll need some modification or trimming without suspension upgrades.