Unfortunately this is simply a current limitation of tyFlow. I hope to get all moblur issues worked out in the future, but I don't have an estimated timeline.
Some users have reported that exporting to XMesh will allow you to get motion blur. And It's also possible that if you set your VRay moblur interval to twice the duration it may work as well (ex: moblur duration of .25, interval to 0.5).
Some users have reported that exporting to XMesh will allow you to get motion blur. And It's also possible that if you set your VRay moblur interval to twice the duration it may work as well (ex: moblur duration of .25, interval to 0.5).