I was able to brew this yesterday, during a surprise ice storm. For some reason I got 93% efficiency into the kettle (I usually get high 80s and had adjusted Kai's recipe for that) so I ended up with OG of 1.058, a little higher than I would have liked but I'm sure it will work out.
About the hops: my Magnums are 10% AA right now, so I did 0.80oz in my 16gal (preboil) volume, rather than 0.43oz of 14% that Kai's recipe (scaled to my batch size) called for. This is a little hoppier than Kai's original, but still less than Jamil's Helles from BCS (last time I brewed that, I used 2.50oz of 4% Hallertauer as bittering in the same size batch).
I left the two later additions as Kai spec'ed - 0.43oz each, however I did not have Hallertau Tradition on hand, so I used regular Hallertau instead.
I'm looking forward to tasting this in about 2 months.