157 is a pretty high mash temp for easily fermentable sugars. Also the crystal malts aren't going to be as good at producing easily fermentable sugars like your base malt does. I also think WLP001 has a tough time doing hard work at 62.
My opinion is that 1.020 might be all you're gonna get. I bet it still tastes good.
On Tap: Dry Hopped Sour Ale
Bottled: Dupont Clone, Brett Saison
On Deck: Kolsch, Summer Saison