I'm back to square one here. After removing BrcmFirmwareData.kext and BrcmPatchRAM2.kext, and leaving BrcmBluetoothInjector.kext installed, I had BT working in both Mojave and Catalina with both Clover and OC. What I found though is that my USB3 ports were not working correctly. Some portable bus-powered USB HDDs would mount, but a bunch would not. I tried all kinds of USB SSDTs and kexts with no luck getting full USB3 functionality back. This issue appeared in both Catalina with OC and Mojave with Clover (that's all I tested). Not only that, after shutting down the computer, cutting power, and waiting awhile, I came back to find BT no longer worked properly. BT showed up in System Preferences for both Mojave with Clover and Catalina with OC, but I could not get any BT devices to actually connect (they would show, but not connect).
So I decided to put Clover back how it was before with BrcmFirmwareData.kext and BrcmPatchRAM2.kext installed. Started Mojave. BT worked again (devices connect properly right away) and all of my portable bus-powered USB3 drives mount.
So then I decided to try Catalina again. Booted from my OC USB into Catalina. This is with onlyc BrcmBluetoothInjector.kext. BT worked, but my portable bus-powered USB3 drives would not mount. I then installed BrcmFirmwareData.kext and BrcmPatchRAM2.kext on the OC EFI and added to config. Restarted. BT no longer works in Catalina, but all the portable bus-powered USB3 drives do mount.
Isn't that bizarre? Why won't the bus-powered USB3 drives mount without BrcmFirmwareData.kext and BrcmPatchRAM2.kext? And it seems whatever BrcmFirmwareData.kext and BrcmPatchRAM2.kext do gets loaded into some kind of RAM temporarily where only BrcmBluetoothInjector.kext is needed until power is completely cut from the computer or it's off for a while, but eventually BrcmFirmwareData.kext and BrcmPatchRAM2.kext are needed again for BT functionality. But if BrcmFirmwareData.kext and BrcmPatchRAM2.kext are loaded with Catalina with BrcmBluetoothInjector.kext then BT won't work.
Any thoughts on this?
Attaching current EFI and an IOReg from Catalina with OC as bootloader.