Originally Posted by
Eastbay1K
Adding to this Q, if one has a long (same ticket) connection and decide to leave the airport for a city visit, will there be any inhibition on re-entry (such as a departure tax not having been paid)?
No.
I traveled through GRU with my dog multiple times, always entering Brazil and leaving the building , then re-entering without any issues. We also were escorted out of the departure area again (re-entering Brazil and going through immigration, the quickest ever) a few times when there were flight delays so the dog could go on an outside break.
The ease of doing this was one big reason for choosing transit through GRU over other routings.