If the animation playback is not smooth in PiView, it's very likes that the frame rate is dragged by Maya's performance. Here is a tip for better FPS.
Once the skeletal assets are finalized and converted into Unreal formats, you may delete the meshes under "Geometry" group or replace them with a low-res version(proxy). This will release the burden of processing heavy meshes from Maya and get a smoother playback.
Remember to check in a version of the asset before you do this, in case you still want to modify the model later.