I have succeeded in producing raw files from chd thanks to numDHC.
I was able to generate this from a MAMEchd in DrumManiaV.
Please refer to this if you are having trouble.
Also, I am trying the same boot method as ThrillDrive3 with P2io, but I would like to know how to decompress or generate EFI when doing an EFI boot.
numDHC
https://github.com/umageddon/namDHC/releases/tag/v1.13
CHD
https://archive.org/download/MAME_0.225_CHDs_merged/