why clearme?
is there delay display ??
Why? Really? Because it has to be cleanMe Region otherwise it gives many different problems.
In my case a bit slow graphics on UEFI then booted fine and installed OS and worked for hours. Then 3rd or 4th boot start giving problems, finally NO BOOT again.
FYIO: No clean MeRegion can lead to a number of issues, including:
A long POST delay (prior to Apple chime and boot menu)
The system hanging indefinitely on its loading screen with the Apple icon and a partially or even fully filled bar
The system being able to boot into Windows/Linux/etc. but never successfully into MacOS or any MacOS installers
The system being able to boot into EFI ASDs but not OS ASDs
Freezing or kernel panics while booting macOS
Error messages during verbose boot mode resembling "busy timeout[0], (60s): 'IGPU'"
The fan always running at full speed
Hard, spontaneous shutdown after 30 minutes
No POST situations
More obscure, fringe symptoms like the webcam not working on some Mac boards.