Followup to discussion from last SRS meeting.
I have my code working, using the open source AHRS implementations.
I did not need to modify the SParkFun 9DoF in any way;
I still have some axis & directions to sort out, but you can see it is working quite well.
BTW, it is using WIndows WPF (Native Windows UI), not a single line of code for the 3D or graphs, just feeding data.