The addition of a blacklist is absolutely fantastic! Now is there a way to do the opposite? Like allowing certain players only specific morphs instead of letting them pick up anything when they kill it?

I also would like that. Would make a great addition to the origin mod (forge). I can execute the morph command using functions in a datapack.
a whitelist would make it easier than adding 300 mobs to blacklist if you use many mods. Or just an add all command.