>> What I'm going to do now is to write a patch to remove the \cset part of
>> the commit and post it, intending to push at some point next week.
>
> Per your request, here is a patch which removes \cset from pgbench. Sigh.
Again, only the removal is a little deeper. This lifts the constraint
about not using empty queries in a compound statement, at the price of
some added logic to detect the last result.
--
Fabien.