Ed, I think the key to what Barry is saying is his use of the term "blocked." By this he means that the center rail of the layout is gapped in places, to create separate blocks, and each block should have only one feed, so that data packets don't hit the loco multiple times.
Barry, I note your use of the term "frequency." This indicates that the data is being sent via electrons at "high" (i.e., greater than 60Hzfrequency). I note that this is indicated in the discussion of packets at www.inetdaemon.com. Especially at:
(This could lead to some interesting discussions, possibly beyond the scope of this thread, about the inter-effect of a 60 Hz train power current and a DCS signal, both going over the same conductor. For example, suppose I'm powering a loop of O-gauge track through, to use an extreme example, 22-gauge wire. I will have a lot of voltage loss. Now I add a DCS signal, microscopic by comparison in both voltage and current. What is the effect on the strength of the DCS signal of its electrons also having to squeeze through the wire??????)
As you know from prior discussions and you having seen my layout, I use a common U-terminal bus all around the layout into which everything--track, accessories, lights--is connected. Hot comes from the TIU into the control panel, where it splits as it passes each toggle switch. In effect, the control panel is a giant terminal block, branching every 2" to 10" depending on the distance between toggle switches, from which one drop per block goes to each block. ED is asking what is the difference between this and a terminal strip which branches every 1" or so.
As I think about your discussion of splitting, I'm inclined to agree, but I don't see that the distance between splits would matter. Splitting would have negligible effect on a 60 Hz circuit due to lack of continuity on an unused branch. But on a higher frequency circuit, like a DCS signal, it could do so because of capacitor or charging effect effect. Maybe I have the term wrong but I seem to recall something that a high frequency circuit has some flow even through not a continuous circuit.
Edit: Barry, this was drafted before reading your immediately preceding posts.