Thanks for all the suggestions. The problem is finding time to load up the bike and get into the hills to try different load distributions. It's not a serious problem, so I can wait until I'm on tour to try to fine tune it. I'll just keep an eye on my rear view mirror and make sure I'm not swerving into overtaking traffic.

Edit: I just checked some notes I had on my bike's frame geometry. It has the same head angle as an LHT or 520: 71 degrees. And my Surly 1x1 fork has 45 mm of rake, same as the LHT and slightly less than the 520 (52mm?). So the numbers look ok there, right?