Export Lipsync Blendshape Animation out of UE4?

I'm interested in the actual blendshape data. In the meantime I found out that it's possible to record joint animation (instead of the blendshapes) with UE4's sequence recorder. So I created a simple rig with one joint for each viseme. From the Playback Blueprint in the Oculus Lipsync example project I created public variables for each viseme to expose the data from the Get Viseme node. In the animation blueprint with the proxy rig I retrieved the variables and passed the values with the Transform (Modify) Bone node to the respective joints. And then recorded the animation blueprint with the proxy rig. Not elegant, but works so far. I'm currently trying to sync the audio which is a bit tricky using the sequence recorder...