The problem
The checks you can run yourself are not the checks that protect you.
When a translated file comes back, you can verify a short list of things without knowing the language. That is useful, but it is not translation quality.
The layout heldTables didn't break Nothing is truncatedNo elements left hanging
None of that has anything to do with whether the translation is correct.
What you can't verify is the rest. Whether a screw came back as a bolt — both real terms, both plausible, one of them wrong, and no way to tell which without knowing the language and the product. Whether a qualifying condition survived into the target sentence. Whether a should became a must. Whether a claim you're permitted to make in one market got stronger in another.
“And when the visible layer does fail (broken tables, hanging elements on a file that was supposedly reviewed) that is a finding about the invisible layer too.