El Coke,
I have to agree with you. It takes a minimum of 8-10 lbs to set up a train, hence the minimum reduction (or first service) notch. The only way that you can get by with any short cycling on extended downgrade is to set the initial, kick it off, then before they've fully recharged, come back with a pound or two more and intentionally "Stick" the brakes. This is termed as using "soft air".
On the ABDW system this works in both power and Dynamic brakes (something the D&S and C&TS never have to worry about).
The only exception that I take to your statement is that "short cycling" can be used often. Without sufficient recharge, you have about three sets and then you're in deep maird.
Of course, there is the backup of the emergency portion of the reservoir on this system, but then you've got to tie the train down before you reset the brakes and pump up your train line to start all over again.
Short cycling doesn't sound like a good practice with ANY air system. Glad I wasn't taught that way.
Rick Steele