As you know it is quite difficult at the moment to find IMU. So I tested this witmotion IMU.

I have rather good results at least equivalent to the bno.
it uses the mpu9250 like the wt901.

the wt901 has the advantage/disadvantage of having the magnetometer activated (and I don’t think this is useful for aog so I see it as a disadvantage for choosing its location far from magnetic disturbance)

the wt61p or wt901 are available and arrive quite quickly.
I made a request to add code. however, it must be proven and tested.

for those who would also like to try comparing, here is the link to the support files