Thanks for the replies.
There seems to be an even division between those who don't care about or don't notice the shadow, and those who do. I think I'd be annoyed by the shadow.
Since posting I've realised that Herse offers the racks for c/pull brakes in 3 types: one (i) as described above that mounts a standing Edelux II next to the tyre; one (ii) with a tab on the left hand side designed to mount a hanging Edelux in the same position; and another (iii) with two 5 or 6 mm mounting points on the struts supporting the rack from the forks. It should be possible to use something like the Soma Wingmann light mount—or, indeed, a Weinmann c/pull brake arm—to one of (ii) or (iii) to raise a standing Edelux to what would be, to my eyes, a better position.
Thanks again. (Unless someone has more to say?)