AFAIK,
If Optimus is enabled the built-in display will be connect to the Intel GPU directly as Internal Display (AppleBacklightDisplay)
If Optimus is disabled the built-in display will be connect to Nvidia GPU directly as External Display (AppleDisplay) if your connector is EDP and Internal Display if your connector is LVDS.
When Optimus is disabled:
- For LVDS case, simply disable Optimus in BIOS then inject Nvidia in Clover, then it shall works.
- For EDP/DP case, there won't be actual built-in screen anymore as your built-in screen will be detected as an external display of Nvidia GPU, so you wont need to inject Nvidia in this case, but you will need Lilu.kext & NvidiaGraphicsFixup.kext in Clover EFI Folder.