> Directional laser beams are orders of magnitude to jam compared to radio wave. That alone makes it of big interest for military applications, even with 500 ms latency.

I am reminded of RFC 1217 - Memo from the Consortium for Slow Commotion Research (CSCR) https://www.rfc-editor.org/rfc/rfc1217

    2. Jam-Resistant Land Mobile Communications

       This system uses a highly redundant optical communication technique
       to achieve ultra-low, ultra-robust transmission.  The basic unit is
       the M1A1 tank.  Each tank is labelled with the number 0 or 1 painted
       four feet high on the tank turret in yellow, day-glo luminescent
       paint.  Several detection methods are under consideration: