71 °C is the temperature that will drop down to 67 when adding the room temperature grains, yes. The grains are also fresh, I bought them only a couple of months ago and stored them in air tight buckets with click- or screw on-lids ever since.

I know about the purpose of a step mash and my last two brew days involved them, yet without benefit. What I picked though up is that given today’s grains, starting the mash as low as 50 might even be detrimental to the head retention as the proteases might eat away more protein than required. But on this, I’m only reciting theory learned elsewhere and can’t speak from experience.