Well, I've resolved my problem through meticulous diagnosis and the cause of my signal issue was so unexpected that I'm posting just in case someone else should find themselves scratching their heads on this issue.
Background recap: on a right turn, my right signal would cancel immediately on the click (prematurely), while on left turns, the cancel would return normally on the return after the click.
Findings: After removing the steering wheel and column surrounds to get to the switch, I manually activated the turn stalk in both directions and manually turned the cancelling ring. To my surprise, the cancelling occured normally in both directions on the return. confused, I reassembled checking both directions as each screw was fastened (thinking that one particular screw may be exerting too much force at a certain point caused the premature cancelling). It all worked correctly up until I reconnected the turning stalk rubber gator to the surround. After removing just the gator, normal function again. So it was the gator; but why? I came to realize that the gator exerts a certain amount of recentering force once the gator is installed in the surround hole AND that it appears the gator is slightly sided in one direction along the vertical axis. I rotated the gator 180 degrees, reinstalled, and everything worked perfectly!.
Since the turn signal stalk is normally centered in the slightly up position on the column, with the gator installed 180 degrees wrong, the recentering alone was causing enough force on the stalk to cancel and return the center when it hit the top click position. rotating 180 put the weaker side of the gator on top.
This could be an anomaly on my turn signal, but if someone is having this problem, it's an easy thing to rule out without any disassembly of the column surround.