The output is only part of the job
Simon’s quantity surveying story contains two distinct kinds of work. AI produced the files. Simon defined the professional requirements and reviewed the result.
An experienced person sees questions that a newcomer may miss: which drawing governs, whether a quantity is plausible, what assumption changes the answer. Those questions belong in the brief and the review.
Pick a test you can judge
Choose a representative piece of work with known inputs. State the standards, format and intended use. Ask for sources, formulas and uncertainty to remain visible.
Compare the result against the checks you already use. Record both production time and review time so that the comparison means something.
Use what the result teaches you
Perhaps it removes a repetitive step. Perhaps the brief needs to be clearer. Perhaps a task needs more information before it can be delegated. A useful experiment gives you evidence for the next decision.