John Widdoss used to say all his reports were summary because he really didn't know where the boundaries are on "self-contained"...it sorta implies that you write the history of the world in one report.
I think the OPs complaint however centers around clients that continue to add "stips" to reports...requiring details that most of us would think the sort of describe provisions that are required in a self-contained report. Extended explanatory text, things like aerial photos ("original" aerial photos for instance), zoning maps, letters from zoning commissions and building codes...etc.
His complaint is legitimate. Why are they asking for such details? It's because they don't trust you. They simply do not understand that when people bid against each other for 72 hr. TATs you will typically get the fastest, cheapest, and least reliable product. So they add things so they can vet the quality within the report. An aerial photo, for instance, should show the adjacent homes and if it is abutted against a factory, a cemetery, a shipyard....they can see for themselves that the view isn't "average". Interior photos support the quality ratings, etc.
Since the low bid losers that they hire cannot be depended upon, the AMCs are "making 'em honest" by requiring things that support the assertions in the report. It is far beyond, "Trust me, I am your certified appraiser." The profession has not earned that trust, largely due to those cut rate, cut quality appraisers who remain abundant in the field.