I am sending a Memcal to Ryan for modification with the socket so I can more easily monitor what is going on directly. In the mean time, the last thing I tried this afternoon was installing a Memcal modified by Ryan eleven years ago, labeled turbo 1.1. I had checked and the injector constant is correct for the 30# injectors currently installed so I figured I had little to lose by trying the idle and off idle behavior while sitting in park. It has more spark advance in the lower and mid range areas of the spark table, which the engine seemed to like. There were a couple small bobbles but most of the time, the engine would zing right up, along with increased timing. The two bobbles were not severe and did correspond to a timing drop to 17 and 13 degrees from the normal 20 at warm idle. I watched the knock counter and it showed zero knock counts no matter how hard I stabbed the throttle. In short, it seems this is at least part of the answer is contained in timing tables without yet knowing what is causing the unexpected drop. Time will tell but for now I intend to spend several weeks at my cottage and this will have less priority for a while.