JBrow, this may seem a little dated but when I was running a Delta P12 in the late 80's it had a three shock setup. I felt that outdoors it worked well. There were no tweak screws and all setup was with the collars. Like many other suspensions, it seemed to work best with a minimum of preload. In other words it liked having a single spring that was able to control the roll while the opposite spring would actually become loose as the other compressed. Just some thoughts.
PK