What worked for me was to uncheck the "Inject Intel" in Clover boot options (which fixed the black screen problem related to Intel HD 630), then I was able to boot the system so I could reinstall the two kexts (Lilu and IntelGraphicsFixup) in L/E using KextBeast - rebooted and all is great once again.
What an easy upgrade, this is my first Hackintosh upgrade experience and it went so smoothly, thanks to all the efforts of folks here, many many thanks!!