Ok the final recipe below. I got 8 extra points of efficiency to boot, this stuff mills a lot like fat Maris Otter. Really nice. Made a shift from WLP001 to Nottingham because I want the malt to shine. 15L was the right setting in BWS - I came in at 5.36, +0.03 over the estimated mash pH. Color is pretty much a middle red to copper color. Should be pretty in the glass.
11 gallon batch
20# Red X Malt
1.5# CaraPils
Used the BWS Pale Ale profile, pickling lime to raise alkalinity, 100% RO
90 minute mash at 152F - had some issues hitting strike temp, overshot to 160F and dropped to 152F
FHW with 1 oz Magnum and Amarillo, 45 minutes lauter
Whirlfloc @ 15 minutes
Whirlpool/Stand 30 minutes above 180F, 2 oz Willamette + 1 oz Columbus
Nottingham, will ferment low at 64F. Will dry hop with a couple of ounces of Amarillo and Williamette.
Looking forward to seeing how this turns out. I can imagine a rich dubbel or a dunkel using this and being really nice.
Thanks everyone for their input.