I created a Unreal Plugin that wraps the Native SDK, and integrates most of the Cubism Framework into Unreal Engine. If anyone is interested in using it, I would appreciate some feedback as well to improve it even further.
With the plugin you can import Live2D models and play motions. Expressions are currently still a work in progress.
It can be found here: https://github.com/stkrwork/UE-Live2D