During Stage 1 install when you ran Disk Utilities to format the hard drive, do you remember choosing “Show All Devices” and then selecting the parent name of your hard drive? And formatting it as MacOS Extended (Journaled)?
I wonder if adding the SAT0 to SATA patch in ACPI might help as well. This is available from the Clover Configurator ACPI screen, from the pop-up menu. I just stepped away from the house for a few hours but please try this as well.
Also, what happens if you ignore the error, power down the system completely, pull the power cable from the power supply for 10 seconds, then boot up again and try stage 2?