Working with two clients -- third won't receive countdown.
IT WORKS! Swapped GZLL client/host roles, fixed bugs.

Someone explain the point of line 149 in sync_client.ino, please.
It acts like a race condition where eventually lines 151-156
get stuck printing "P0L2R1", which  makes  precisely zero sense.
R should equal either P or L. Or something like that.