I think that the scene shown is a great textbook example because it shows how seemingly simple locations contain quite some complexity, but not because the scripts are so complex but because the prototype is.
The GWR where classic for installing a Forrest of ground signals.
The SR was very economic with ground disc and show how little was required to meet the regulation.
This have been a delight to see how both companies approach signals and is reflected in the route.
The wrapper is nice case for do as you please. You could span KWL16 and 13 to beyond switch 9, but then you would need an inner link for each beyond switch 12 or we might miss some very short light engine that reverses at 12 without touching the signal links beyond link 9. So it is just the same total number of track links, whether you use a wrapper or not. Also whether you prefer to have the wrapper depends on whether you easily get the links right or not there. If link 0 does not follow all the numbered links there, you have a hard to detect problem.
The reason I use this method is spanning signal links across link 0 for KWL11 seems to affect the reaction time for KWL11. With no links across and treating each crossing set as an independent set of signal gives the best results.
Once the signals are working you will find they prepare up to 3 stations ahead.
In the down direction, we have no choice but to have two ground signals, blame GWR. 8 clearly is a home signal (independent disk in terms of my scripts), 11 could be a dependent disk if you like, or just the same as 8.
I could use the dependent disk but I prefer not to use them unless required as they always display one route or the other. Seeing a green light on the other track in the reverse direct is confusing and something I prefer to avoid.
Your statement about dependent discs in the Reference Manual 1.0
5.4.4 Dependent disks
Their prime drawback is that they do not constitute block signals for AI, so reversing to the wrong
line to let another train pass will shock AI trains far and wide. Like section signals they clear
without giving information about the next disk. They are meant to be placed beyond a home signal
which would not clear unless the path is set to the next running signal. So you would need the first
disk in a row of disks on the wrong line to be an independent one, and follow that by dependent
ones. But since every crossover could be the starting point of a wrong-line run, this is not an option.
In short, dependent disks are not the first choice for wrong-line signalling.
This is a case here the dependent would be protected by the independent discs and arm.
My reason for not using is the disc display.