The ramp up to 170 looks like a mash out to me. I don't do a mash out batch sparging. For me, I would mash at 150 for 60 minutes, vorlauf, collect first runnings, add sparge water, stir, vorlauf, collect second runnings. I try and have my first and second runnings about equal. If you're looking to collect 7 gallons total, I'd target about 3.5 for each running.