OK, the results are in. Bottom line: closest so far: if it stays this good, I consider it FIXED!
Here's the setup showing how I cooled it and leveled it. I left the props on because I just don't like taking them off and retightening them a lot as I'm concerned what that does to the threads over time:
View attachment 53775 View attachment 53776 View attachment 53777
And the result, pointing N, W, S, and then E:
View attachment 53778 View attachment 53779 View attachment 53780 View attachment 53781
About as close as you can get. That last one (pointing east) has a minute clockwise rotation, but that's really splitting hairs. I also took a 7 minute video while flying around and other than the type of hair splitting above, it was level the entire time with me flying about 1000 feet from home and doing a lot of yawing.
Here's hoping it
stays that way! Oh, and even though mine was more of a "cool" IMU calibration, the warmup time is now something on the order of 10 seconds. It was like 2 minutes before. So that's a huge improvement!
Mike