Update: I received my third ver 2.0 AHRS board from crewdog yesterday. I had already updated my ssd to the latest zip version 1.6 ver**e842. Initially after calibrating the new board it continued to drift. I then downloaded the ssh version (same build number as the 842 zip file) and ran the ssh update. It took the stratux about 10 minutes to stop blinking after the ssh update. I rebooted the stratux, then recalibrated the AHRS board, set level, set drift and waited.
Whether it was the third replacement board or going through the steps above I can't say but the AHRS - although not rock steady - seems to be pretty stable. In any case a major improvement over the previous results where the board would show me at extreme bank angles in a very short time.
Granted my older 1.1 AHRS chip is rock steady. I let the stratux run overnight and tested it again some 18 hours later - it was still pretty well aligned with my calibrated setup position.
I'm planning on testing my other 2.0 boards tomorrow and will report if the programming steps make any difference.