Did more testing and here is what I found - dynamic directional light doesn’t work on mobile in general. Stationary directional light works and HISMCs render properly when using stationary light. HISMCs do not support lightmaps (yet?).
The problem is that stationary lights require distant field shadows for static lightinfg, which bog down performance a lot more than lightmaps.
So, the fundamental problem is that HISMCs (or batching of static meshes with LODS) are essential for mobile VR and creation of interesting and content rich worlds without massive performance drain, and yet they are no use in mobile VR because they do not render with static lighting 