Heh.. there's no pull requests against the kernel... Linus will hate you if you do that. But one could sent a patch to the kernel mailing list
However, since this is in a core part of the usb logic, and countless devices have had no problem... I doubt a patch increasing the timeout or adding an api that takes a timeout value would be approved (since so far only a single device would need this).
But I can add a boot quirk in snd-usb-audio if it comes to that - at least there's precedent there for device specific quirks.