wrote:
If the pilot uses the glideslope for backup vertical guidance to give a
smooth transition to the final segment (while using the altimeter
readout outside the FAF to ensure he doesn't descend below 1800) then
what's wrong with that?


Nothing wrong with that.


That isn't really correct either. There's no necessity to monitor
the altimeter at SCK because there's no step-down fixes or other
crossing restrictions at issue. Above 1800 feet on the glideslope, the
glideslope is advisory, but the pilot is perforce satisfying the =1800
foot minimum altitude requirement. Below 1800 feet the glideslope
becomes primary. So in practical terms nothing happens at 1800 feet.
There's nothing to monitor. (OK. I know, you part 121 types have now
reached a point where the weather can below minimums without
necessitating a miss.)

At *Stockton* (the subject of the question), there is no legal issue.
At LAX on the Civet arrival, and other situations where there are
step-down altitudes on the localizer outside the PFAF, there is a
potential issue. The step down minima take precedence over the GS
altitude.

We are procedurally in violent agreement. Nonetheless, the G/S is not
primary prior to the PFAF, any minimum altitude constraints
notwithstanding. That is the legalese of Part 97. I am just the messenger.