So I took a look... Now let me preface by saying that unfortunately I didn't keep much of my own personal hack's EFI data from Mojave... A bit of this had to come from some quick and dirty research. Give this EFI a try... I did update your SMBIOS to iMac19,1 with the use of both your iGPU (headless) and dGPU - so keep that in mind... If you're already signed into iServices then you can boot from the new SMBIOS and it'll ask you for your iCloud password again - everything should continue working. If not, make sure you clear out everything listed
here. I also removed USBInjectALL and replaced it with a custom kext for our motherboard. It is specific to iMac19,1 and it also probably doesn't have the ports active the way you want them but we can figure out the exact ports later and I'll edit for you. I also installed TB3 SSDT so that should also be usable as TB3/USB3 but no hot-plug yet.
Also, the community has now fixed NVRAM via an SSDT to replicated it being native to Z390 boards, you need to update your EFI so it's fully supported. For now, I just left it as is with EMUvariable driver in place. If you want to fix your board so it supports native NVRAM, follow the instructions
here. I realize both of those guides are for OpenCore but you can relate the info just as easily to a Clover install.
NOW, it is extremely hard to come up with a fresh EFI on the fly without sitting in front of the computer/hardware so use the posted EFI with caution - I would format a USB thumb drive and boot from the EFI of that or use a
separate vanilla install so your original stays intact in case you want to go right back to it...
DON'T DO ANYTHING WITHOUT A BACKUP! ALWAYS!
Honestly your original EFI was a bit of a mess. There was a ton of unnecessary stuff in there. Going forward I'd love to help, but let's take it to Discord or another method so we don't hijack the thread entirely. My username is the same on Discord.