...Arran, surely DB spokes would help relieve the strain as they are more forgiving in the first place and build up a stronger wheel than plain gauge. Or are the Alpina Tripple butted I forget ?
DT Alpines are 2.3mm at the head, 1.8mm through the middle & 2.0mm at the threaded end. Gess you could call that 'tripple butted'?
...As to the origin of snowflakes, I had heard that BITD a wheelbuilder had run out of the correct length spokes and discovered that adding a twist to spokes intended for 700c road wheels shortened them enough to use on 26 inch MTB wheels. People liked them and the fashion quickly spread.
You only need an extra 4mm, surprisingly enough so the story you speak of is surely a myth (don't think it qualifies for 'urban legend status...).
* '89 Nishiki Alien 17/19"
* Mantis Valkyrie-EC 18"
* Titan 1/2 Trac 18" (Stay tuned to this channel...)'89 Titan 1/2 Trac, '90 Nishiki Alien ACX (NOS, M735), '90 Pearson Kea, '91 Nishiki Alien ACX (M900), '91 Haro Extreme Comp (M735), '91 Milazo Rock Comp II, '91 Mantis XCR-EC, '92 American Comp-Lite (XC-Pro), '12 Soma B-Side (650B), '14 Cannondale Evo Hi-Mod 1 DA9000, '15 Cannondale Trigger 27.5 Carbon 2 (XTR)