I tried the boil down approach once with a Scottish ale. It was a pain in the a$$ and I don't think it added anything to the flavor. I'm not sure I boiled it down enough, but I did as much as I had the time and patience for. Now I just use Golden Promise with a bit of Special B and a bit of roasted barley.
Interesting. I'm wondering why boiling some wort was such a PITA? I did this a few months ago with a Brown Ale and it was just a matter of ladling out some mash and reducing it in a small pot. The process gets started as the wort is coming to a boil and is finished long before the boil is over (for my 3-gal batches, that's ≈ 48oz reduced to a syrupy 12, give or take). I won't argue the fact that it may not have added much to the flavor as I had nothing to compare it to, but I thought it did. I'd happily try this again and I would think *IF* boiling down adds anything, it would show up in a simple 60/-.
I'm personally not a fan of Special B and honestly, I don't see why a 60/- needs anything other than a Pale malt and a touch of roast. 2 grains, period. Flaked Maize and Invert show up in Pattinson's blog, but I don't think either are necessary. Does the flaked maize help put the "light" in the Scottish Light? Personal preference, I suppose.