The best way to get only Perksaver only is to search using that function instead of best available. It will also pull up Perksaver First class which is fewer miles than PerkPass coach on domestic flights.

Each market is different in what they offer in PerkSaver availability. And of course what's available is very dynamic so people often check back very frequently. Since PerkPass is basically always available as long as there is one seat open, waiting and searching often can be fruitful, though very time consuming.

Good luck!