Thing is, sprung suspension allows plenty of tilt - sometimes too much so.
CSB suspension started to become a thing some years after Rice's book was published; it's a bit more controlled than coil springs.
I think that AL was absorbed into the SSM range
It's quite telling that, back in 1993, Iain Rice didn't venture into discussing sprung suspension in his book - I think he thought it the work of the devil!
An Australian P4 modeller friend of mine who is currently visiting the UK says that the FREMO module idea has taken off amongst the Aussie OOn9 community and some quite ambitious networks have been put together at meetings.
I quite like the idea of a junction station layout/module - trains can call and then go off on two/three/four different route options.
Claremorris had five exits at its peak....
That's why FREMO module networks might actually be a practical way of achieving the ultimate layout...
Me, I keep thinking of stations like Claremorris (with the pre-1975 track layout), Macmine Junction, and so on....