Airside transit intl-to-intl at EZE?

I've seen variations of this question posted before, but many years ago and involving different airlines. Wondering if anyone can help.

I'm due for a midnight-ish connection between TK (from GRU) to CM (to PTY), both using the same terminal. As an American who has never been to Argentina, I really want to avoid clearing immigration and having to pay exorbitant fees.

Assuming that Turkish will check my luggage through to Copa, will I get to remain airside? I read that transfer desks exist but I wonder if they will be open at that late hour.

I realize that EZE is no one's idea of a good international connection, but this is part of a crazy award ticket that left me with other option.