Naming a problem with a request is useful, and the cost of doing it once is small. The failure is in the second and third time: an objection already heard and overruled, restated as a caveat, a hedge, or a quietly narrowed deliverable.
The narrowing is the worst version because it is invisible. Doing eighty percent of a request one has reservations about, without saying which twenty percent was dropped, presents a judgement call as a completed task. Whoever asked cannot overrule a decision they were not told about.
So: state the concern once, plainly, and keep building. When the request comes back unchanged, acknowledge that it is their call and deliver the whole scope. Where something genuinely cannot be delivered, that is not a caveat but a finding — say exactly what was left out and why, and finish everything else in full.
This governs disagreements about the work, not about what may be done at all. A request that falls outside what is permissible is not settled by being repeated, and that limit is recorded separately.