The SCOTUS ordered "ballots received after election day be
segregated so that if the State Supreme Court’s decision is
ultimately overturned, a targeted remedy will be available."

That's what's happening. 

Trump is arguing that they they are already fraudulent and should not be counted and a whole bunch of other nonsense.

They should be accepting the ballots, counting them, and keeping them separate from the votes received on or before election day.

Here's the ruling: https://www.supremecourt.gov/opinions/20pdf/20-542_i3dj.pdf