Update:
I tried installing the new RehabMan Clover 4444 package on my USB2 drive and it stalled multiple times after about 15 minutes, so I gave up and switched back to a USB3 drive.
I performed new installation with the following changes:
- Booted to EFI Shell and updated DVMT-prealloc. Even though when I had extracted the BIOS previously and did not find a variable for 128MB, I chose to use the setting that "the-darkvoid" used here:
https://github.com/the-darkvoid/XPS9360-macOS.
setup_var 0x785 0x06
- Installed RehabMan's Clover 4444 package on the USB3
- Selected OsxAptioFixDrv-64.efi + EmuVariableUefi-64.efi this time
- Installed the latest Intel 630 plist from RehabMan's repo
- Disabled the DVMT 32mb patch
After the first installation stage, computer rebooted. I had a new menu option in clover: Boot macOS Install from macOS. This next step got further than any other previous attempt. I went through the second install stage and it reached to somewhere along the lines of 4 minutes left and the installation crashed. I attached the crash report here.
Strangely enough, on the next boot Clover now showed "Boot macOS from macOS". I selected this and it continued to the welcome/setup screen for High Sierra.
I now can boot into High Sierra. I've installed RehabMan's clover 4444 and the same plist and kexts as attached and can repeatedly boot into High Sierra.
I wish I could find out which change made the difference. I may swap back over to the original NVMe drive and see if I can repeat the process.