I have an overall "Masters" folder where all my exports go. Within that folder, I have a folder for each client.
Masters/Client1 Exports 2021
Masters/Client 2 Exports 2021
Masters/Client 3 Exports 2021
So far, I've attempted loading up a project for Client 1, changed the export path. Then closed the project, loaded up a project for Client 2 and set that export path, then closed project. When I load up the Client 1 project, the export path is for Client 2. Anytime I change either relative or overall path, that's the path I see no matter what Client project I open up.