Check out this archive
for 0x3c file with metadata 0x20 bytes (also all files of 3c type have 0x20 metadata).
To confirm compression flag try to make debug edat/sdat using rar archive (or some other archive).
About hash keys: we can decrypt, recrypt and encrypt version 2 and 3 edats/sdats using your algo (except 3c edats for now). And we can decrypt edats version 0&1. But we can't recrypt or encrypt this edat because of headerHash from original files doesn't math to cmac computed with usual algo.
And about devklic in version 0&1. There are a lot of trial games using "license pkg" to unlock full functionality - a package file contains of only one edat file. This edat is version 1 and type 0x00 and placed into exdata folder (near rif files).
I have game using this type of activation and contains some more edats. And I can bruteforce devklic for others edats but not for this "license" edat.
UPD: Yep you're right, I'm used wrong devklic for this "license" edat, devklic for it is in vsh. And keys for ps1 games and minis.