Apple might be able to fix this by asking the user if they're using a case,

Anyone using a case thicker than ~2mm will probably sufficiently reduce the surface SAR to bring it into compliance.

One might imagine a software update that asks if you're using a case. If you choose yes, nothing happens. If you choose no, then peak transmit power is reduced by 1dB (which will reduce upload speeds ~20%, and may reduce range too)