If you took Panamanian money back to the USA it would probably go through vending machines with no trouble and you wouldn't be cheating any body as the value is the same, though the owner of the vending machine might not like it.
In Panamanian stores and advertising they don't use the dollar sign symbol $ to advertise price. They use a B/ to indicate Balboas. But you can pay with the Yankee dollar and Panamanian coinage and nobody thinks twice about it.