Leaderboard

Check FAQ. Catalina has extra protection that needs to be disable 1st

post debug file

Yes, it should auto switch from Internal to Headphone and vise versa if headphone is inserted and remove. The kextcache log and IOReg file you attached in the debug file shows no existence of CodecCommander.kext. Google for the kext and install it to /Library/Extensions Repair permissions and rebuild cache. If that still doesn't work, change the layout-id in Config file under devices/properties from 12 to 18. No, as you can see in your system information under display, you'll see both graphics. It's also showing in your IOReg file. Try adding boot arg -wegnoegpu to Config file If that doesn't work, we'll need to disable it via DSDT/SSDT patching

Conflict in your Config and DSDT file. Here's the fixed files. Not sure if sleep will won't on dual graphics enabled. Will have to check with the OP. In your kext/Other folder you have 2 USB kexts, USBPorts and USBMap. Should be one or the other, not both. But looking at USBPorts.kext, it's not config for this system, it's hardcoded to IMac14,2. M6800_audio.zip