hiropa

Sadly got the same results with that EFI. 

But in the meantime I experimented a bit with the Config and had success with the following:

Both displays are working, Hotplug is also fine, but HDMI Audio is still an issue. It shows up in the menu, but no sound is played.

As an update: I now copied the RTC fix and the additional Touchpad changes from 0.7.4 of angelts EFI and added them to the 0.6.9 version. Big Sur is now working fine with both screens and no CMOS reset issues. For some reason HDMI audio is not working and Monterey won't work because changing the model breaks the config.

This is the entire injection. It was taken from Angelts 0.6.9 EFI and not changed.  It also has always been 4 ports. 
The physical ports on this Laptop are one VGA and one DP. But it also has a docking Port where I don‘t know how many ports are in there.

No luck here either. It only boots if I reset the frame buffer values to the ones below, which work fine for the screen in OC 0.6.9 but not in the later versions.

Sorry, it's not even booting with it. The Intel Framebuffer kext causes a panic.

Its always connected but it might have slipped to standby while rebooting. I just created the file again just to be sure and updated the post above. Additionally I also created one with the 0.6.9 configuration where it is working.

MacBook Pro OC0.6.9 EFI.ioreg

Actually its a DP -> HDMI Adaptor, as the Probook has no HDMI Port. The crash happens if I pull either the adaptor itself or the cable from the adaptor. 

I attached the IOReg file. I also tested a bit and noticed that the last working version was this, but I could not spot a particular change in the config file. I did however try to copy the frame buffer entries from Device Properties from 0.6.9 to the current ones, but with no success. 

MacBook Pro (2).ioreg

No difference, sadly.  It still goes black instantly with a panic on Intel Framebuffer.

Thank you so much for the latest EFI posted here. This is working much better now. But a new bug that occurred to me is that every time I pull or plug the DisplayPort Cable, the laptop resets. Do you have any idea where this could come from? I already checked GPU setup in config but could not find any changes there.