They can't tell if you're running an ISO unless they someday update the client to send extra details.

An ISO is mounted so that the PSP thinks it's a UMD. Therefore, no-one can tell remotely that you're not using a legit disk.

And why are you using fastloader? That's ancient history!
Update to 3.03 OE-A, then to OE-B and you can run them from the game menu, without region restrictions, and without a UMD needed. Do not update to the official 3.03 firmware! Doing so could relieve you of any chance of running homebrew ever again.

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