ok so... blegh. as i suspected, using the toradex recommended wiggle layout results in the extension of the use of wiggles for well over 150 possible 200 mils. 0.2 inches! that's over 5mm!
the use of only a 45 degree bend basically results only in 2 * (2-sqrt(2)) * 7 or so being added to the length. when you use a U-shaped wiggle that becomes 2 * (2-sqrt(2) * 7 _and_ 2 * (sqrt(2) * 7 _and_ whatever length is on the uprights of the U.
getting fed up of doing these by hand. i'll use the accordion feature. it makes them curved but at least it will be a regular / fixed distance... i wonder if i can switch off the curves... yes you can! ok i'll give that a shot.
l.