That's a pretty good article, with good explanation and good points, but I disagree with their conclusions (and I have a lot of respect for all three of the authors). For street or high speed, SR. For crawling, shackle forward.
What many have found is that as a SR pulls it can load and unload causing bouncing, whereas shackle forward lets the front axle simply pull. Think if it also as the axle pushing on the spring vs pulling on the spring. In a SOA application it's worse, which is why a ladder bar is usually needed. Bouncing sucks, and at the end of the day, getting up the obstacle while burning a third less calories is what it's all about.
That's what many have observed, including myself, and I was a big proponent of SR. Maybe by staying SUA it'll work better for you.
YMMV.
btw, looks good so far, nice progress!