@msw it's not a loophole. AGPLv3 is basically just GPLv3 + clause 13, which is "if you modify the Program, your modified version must prominently offer all users interacting with it remotely through a computer network an opportunity to receive the Corresponding Source of your version"
You have to make your fork advertise its source code. But there is nothing that prevents you from running that fork behind an HTTP proxy which then strips this offer.