If you guys follow CK2 reddit you might have noticed this one. Yeah, a RTK mod has finally taken off.
Not available at Steam thanks to size limitations (+200MB), but you can grab it from moddb.com.
It's compatible with 2.4.4 and 2.4.5, and you can use an addon that uses the asian facepacks if you own them.
Basically, the mod is still missing most flags and some historical stuff, like relatives to many characters, which can make the first sucession quite uneasy. The mod is at version 0.87, version 1.0 should include all the other flags and etcetera. Imperial bureacracy system is planned, for now the Emperor is the religious head of Confucianism only.
If you are planning a Xianbei/Xiongnu/Wuhuan campaign, be warned playing as a nomad here is simply too difficult thanks to many factors.
Anyways, enjoy!