I think some of this issue is that there is not much in the way of “low hanging fruit” any more when it comes to fuel saving initiatives, therefore we enter the realm of dubious procedures which may or may not produce positive results but certainly complicate the operation.
As wiggy points out above, intelligent on-the-day management of the flight profile in response to up-to-date information is in reality much more important.
My airline has, at various points, brought in SE taxi, delayed APU start, lower flap landings, variable CI, fuel saving apps, etc. A rough calculation showed that if I did a visual circuit every 6 months as opposed to a 12-mile ILS, it would save more in that period than all of the above procedures combined...