Thanks, Steve! Exceptional detective work and electrical analyses!
Also, I have no experience with Fastrack, so your additional insights are also very helpful.
Finally, if I understand the implicit summary of your electrical conclusion, each section of Lighted Fastrack is essentially a 10", complete "insulated block", with that individual track's lighting activation accomplished completely within that track.
Although not important, I still don't understand how the random gaps in the outer rails caused by not maintaining one continuously grounded outer rail don't break the circuit in parts of the layout.
