Interesting, since january this year I am working on the same thing 
But I am not trying to do it like in Black Desert because I want to make it compatible to Unreal’s networking and compatible with animations for the mannequin selling on Marketplace (because I am not a good animator).
The problem I see on Black Desert’s system is that it is all “local”, not stored on servers, and the rigs are different for each character class which is weird for a MMO; so instead I focus on making something along the more classical systems that came before.