Nice write up. Your links in mm were 112.5 (oem KDX), 117 (oem KLX250s 06-07 only), 119 (oem KLX250s 09-15), and several longer sizes. Switching from 117 to 112.5 provides a whopping increase of 1.5" of ride height on the rear. Having some 114mm links might be just the ticket.

 

It's 13/16" instead of 1" on a 2006 or 2007.
2006-2007 Kawasaki KLX250S Raising, Lowering Links - $21.50 : burkhartcycle.com, Motorcycle Parts and Accessories

 

Kouba wrote back and said that the 112.5mm links are as short as he could make them.

He also said that his KX100-1 links are 115mm eye to eye (providing ~1/2" lift), but have smaller bolt holes. He said the KX100-1 links could be modified for KLX link bolts.