even plan locking itself would be a welcome feature. we've had multiple instances of plans going haywire (never traced it down, but 99% sure it was after autovacuum analyze) impacting prod and getting back to normal after a manual re-ANALYZE.
I haven't had much use for plan locking even after MS SQL server got it, even though its a nice feature with being able save load plans from a file etc.
I just like good set of hints since they are part of source code and I can put comments and see why they are there in source history later.
if nothing else I would love to have that just so we don't end up debugging heisenbugs that occur and then disappear when you try to find them (or we can't rule it out when we test the same query and it magically starts performing well).
