Ok got past the BIOS issue, now I am facing this issue. Still waiting for root device, however the last of the verbose log reads like this before it switches to the crossed out circle.
I just built a Hackintosh with the Hero XI (Wi-Fi) BIOS 1105, i9-9900K, Sapphire RX-580. I ran into similar problems with macOS booting. SMBIOS is set for iMacPro(1,1).
Things seem to be running fine now after MUCH EFFORT.
I've made four other Hackintoshes using Gigabyte motherboards which were simple compared to this board!
The attached zip file contains my EFI file. I've removed my SMBIOS Serial Number and SmUUID which you can regenerate using Clover Configurator on the config.plist.
Under the Acpi section is a patch - "ACPI Patch" that was required for me to get through the macOS booter without hanging.
The EFI/CLOVER/kexts/Other folder contains USBPorts.kext which sets up my USB ports. I disabled board ports 03, 04, and 05 in BIOS (Advanced Menu/USB Configuration/USB Port Disable Override) in order to keep under the 15 port limit, and activate two USB ports on my case, and the rest of the MB ports.
Also in the zip file is Jul 11 2019 BIOS_settings.txt which is a long text file describing all my current BIOS settings.
Also in the zip file is CMO Jul 11 2019.CMO which can be put on a USB thumb drive, and used to reset all the BIOS settings to the ones I use by booting into BIOS setup then going to the TOOLS menu selecting ASUS User Profile - Load/Save Profile from USB Drive, and select the thumb drive inserted into an active port.
You probably want to use this same Tool to save your current settings in your BIOS BEFORE trying to load my settings so you have something to revert to in case of problems without having to start from scratch.
Note that I have set up my BIOS to overclock using ASUS's AI. You can revert those settings.
Hope this gives you a starting place.
Good Luck