That is true but the practically ubiquitous mandated use of these forms in their present versions and the lack of flexibility broadly present amongst AMC's and lender clients cause problems that cannot be easily dismissed by pointing out the flexibility that USPAP provides for appraisers.
Eggzactly
In order to use these forms in a responsible and ethical manner a reviewer has to be aware of these problems and work around them, much the same way we work around the problems that the GSEs have baked into the other forms.
One thing that's not apparent to many reviewers is that reports only indicate to what the appraiser did, not to what they didn't do. An omission in a report is just that, an omission. The omission doesn't prove that the appraiser didn't perform that step; all it proves it that the info from that step - if performed - was omitted from the report.
I can't tell you how many review assignments I've been given that were "created" by report omissions. Not enough info in the report for a reader to understand what's going on. I would look at these reports, check out the info and search for alternatives only to find that there was nothing unreasonable on the development side, the report was just too light in terms of original writing and explanation for a reader to develop an opinion of credibility.
Where the GSE review forms exacerbate this problem is they make no distinction between reporting and developing problems, or between critical errors vs non-critical errors.
For example, not addressing exposure time in one of these assignments is a technically a USPAP violation, but for most clients and users it's usually not a critical problem that warrants kicking the report back for correction. A reviewer would do well to note the omission in that context, as a minor problem; and then send a note to the appraiser to explain it and tell them not to do it again. You don't want to encourage appraisers to keep on making the same mistakes over and over again, but you also don't want to slow the approval process down over a couple of typos and minor reporting issues that can be resolved at the review level.