Ultimately dust would be up to 1 wei per user per epoch, we would need 1 Million Users Per Week to have 1 USDC worth of dust.
Even in that case, it may be best to change epochs to once per month rather than deal with dust as you can see below the increased gas cost greatly outweighs the saved dust.
Run the tests yourself
https://github.com/GalloDaSballo/badger-onchain-rewards/blob/feat-dust-handling/scripts/dust_simulation.py
