We currently use prepared statements for most of the work an app does, as an SQL injection protection and for other reasons.
There's one statement which can't be prepared:
SET LOCAL myprefix.mysetting = 'my setting value';
Ideally, I'd like to be able to do
PREPARE test(text) as SET LOCAL myprefix.mysetting = $1;
but this isn't supported (currently on PG 9.3)
I suspect the answer is 'no' but no harm in asking if it's likely to be considered in future. I can't see it here: https://wiki.postgresql.org/wiki/Todo