A couple questions about ordered-set aggregates

I find I am allowed to create an ordered-set aggregate with a non-empty
direct argument list and no finisher function. Am I right in thinking
that's kind of nonsensical, as nothing will ever look at the direct args?

Also, the syntax summary shows PARALLEL = { SAFE | RESTRICTED | UNSAFE }
in the ordered-set syntax variant, since 9.6, though that variant
accepts no combine/serial/deserial functions, and there's also
a note saying "Partial (including parallel) aggregation is currently
not supported for ordered-set aggregates."

Does PARALLEL = { SAFE | RESTRICTED | UNSAFE } on an ordered-set
aggregate affect anything?

Regards,
-Chap