Yes it is frustrating!
We have been caught slowing to the SLP speed and admonished by ATC for slowing despite no speed control ( as it turned out they had a bunch behind!).
I love the one about the pilot who overheard the LCO ask for 05 when the hold was in use etc etc. Unless cleared to the hold fix and told to hold or given an EAT, I don't know that the hold is active. In the absence of an EAT, why not chance your arm, you might be in the right place at the right time...........or has ATC become the new "wait your turn" system despite other options available?
Cough,
We, when arriving via Kathy have worked on the basis of getting steered round the danger areas on as short a route as possible including S of GWC to Holly - Willo and planned descent accordingly. It does not always happen that way but having planned for the minimum distance we can easily adjust the profile for any "extended" routing.
Can't rely on the FMC to tell you exactly when to drop but with practice, it gets easier.
Regards,
DFC