I am pretty sure we cannot combine Porzingis with another contact to bring back one bigger contract, due to the second apron restrictions.
I don't think we should trade him. Why sell low? Sure, he only plays 60 or so games per year but I still like his game. I assume they can figure out this illness thing before the start of next season (if they can't, he will never pass a physical). Yes, his minutes need to be heavily managed in the regular season but so what. If we can make a good deal (whatever that means), sure, but no need to dump him in my view.