I could not find any help on this subject but I recently noticed that the RPI4 OS had moved the new bootloader firmware from stable to critical and the Raspberry installer now will install directly to the USB3 SATA drive and boot.
So I just tried to do the same with LE 9.2.5 and it worked with no changes. However, I had to install the LE 9.2.5 image to the USB3 SATA drive using the Raspberry installer and not the LibreELEC installer. the LE installer would not recognize my USB3 adapter and SATA drive.
It took a while to resize the 500GB drive, but then on reboot it worked fine.I did have to put the hdmi_enable_4kp60=1 into the /flash/config.txt file but that was it.
