The new APFS relies on a firmware update to boot APFS disks but Apple obviously is never going to release firmware for older "unsupported" Macs although many models like the cMP3,1 can run High Sierra fine with a little modding/tweaking (thanks dosdude and foxlet). Back in the day, some kind person released a way to update the 2009 MP firmware to the 2010 version, giving those old 2009 Macs a new lease on life and keeping them out of landfill. Is the effort to reverse-engineer the firmware for these older Macs a much harder task than the effort needed to develop hacks/alternative bootloaders supporting APFS? Are there no retired Apple firmware engineers out there who could give advice, or is this a violation of Apple's IP? Is the firmware encrypted? What exactly is stopping hacking of firmware for older Macs?