The BIOS that has locked the AHCI is currently cryptographically signed by Lenovo.

Currently, one user had successfully installed Linux on their device by manually flashing their BIOS by soldering a chip programmer onto the actual chip.

They flashed a version they manually modified the BIOS by reverse engineering and hacking the code to get around Lenovo's goto stmt, restoring uesr access to the Advanced settings page.

So, is this your idea of supporting it ourselves?