I've noticed that a lot of flight controllers have multiple IMUs and Barometers, which makes sense from a redundancy standpoint. But the interesting thing is that they use different models of IMUs. For example, the Pixhawk 6x has an ICM-20649 AND an ICM-42688-P AND an ICM-42670-P.
What is the purpose of having different IMU models on the same board? Is there some sort of signal processing advantage? If so, how does that work, and how measurable is the advantage?