Benchmark scores are treated as evidence of LLM competence, but the same knowledge can yield different scores under different question formats. MCQs provide objective and scalable scoring, but their answer options can turn recall into recognition through answer-option scaffolding. Open-ended constructed response questions (CRQs) remove answer options, but their scores often depend on human or LLM judges and rubric interpretation, introducing judge-dependent scoring. This creates a trade-off between removing answer-option scaffolding and retaining objective scoring. We study whether this trade-off can be reduced through Constrained Structured Response Questions (CSRQs), a structured-response protocol that removes final answer options while preserving deterministic scoring. CSRQs use multi-select, ordering, and matching outputs as auditable answer spaces for exact verification. We evaluate CSRQs using converted knowledge benchmarks and MyCulture, which is, to our knowledge, the first Malaysia-centred cultural benchmark in Bahasa Malaysia, with parallel MCQ, CSRQ, and CRQ formats. Across benchmarks and model families, scores change when the evaluation instrument changes, i.e., scores drop after answer options are removed, and CRQ scores vary across judges. These findings suggest that benchmark scores should be interpreted as products of both model capability and the test used to measure it.