I know the UCs require all scores, but I was wondering if they just use the official report as proof to check with the highest score(s) menteioned in the actual UC application. Or is the testing history actually used to justify part of the admissions (like amount of times taken and previous scores)?
Although you self-report your highest score from a single sitting, they will use the official scores obtained through CB to verify the information. They are only interested in your highest score and I have known many applicants that have taken the test 3+ times. Your testing history will not be held against you if you have some low scores.