It is scary to think about 1) how much control CBP officers have over the fates of people entering the country especially on non-citizen statuses, and 2) how little they know about the rules affecting the latter.
E.g. I've heard of CBP officers not knowing that Canadians don't need to get a visa to enter the US. Also heard of CBP officers not knowing what "Massachusetts Institute of Technology" was on a student's F-1, and had to ask around to confirm that it was a legitimate school. And many more.
Maybe universities should consider adding an optional box to specify if the applicant is willing to give up their potential seat for an affirmative action candidate. /s
Your experiences closely reflect mine for GCP. Some of the tools, although amazing in and of itself, often have some minor flaw that makes the user experience extremely inconvenient when you encounter it many times. The simplicity of the inconvenience only exaggerates the frustration.