Hello Joe,
-TIU is Rev. L. If that’s not what you’re asking, let me know.
-signal strength is 8-10 in all places.
-Yes, loop is broken on opposite side from power connection by an Atlas insulated rail joiner on the center rail, meaning that the distance from power to insulator is the same on both sides.
-None of the locos have smoke units.
-One lighted caboose... I’ll try without it.
-Duplicate responses YES... the middle loco and the head loco both shine the headlight when in forward direction... something definitely seems of sync in that way.