How to make use of linear acceleration and gyroscope data?
You integrate accelerations to get speed and integrate speed to get position. So if you have angular speeds or even orientation, I don't see any use for angular accelerations. That does not mean the unit does not use them internally when calculating the angular speeds and/or orientation.

The linear accelerations can be used for dead reckoning. Airliners, and increasingly any plane with glass cockpit, have inertial navigation system that integrates the accelerometer and gyroscope data to keep track of position. It used to be primary means of navigation over ocean before GPS and now it is still used as backup if GPS signal is lost and for compensating errors by cross-referencing.

The lateral acceleration is also shown by the slip-skid indicator (used to be accompanied by turn rate in turn indicator, but glass cockpits often only have attitude indicator provided it is non-tumbling and maintains precision at unusual attitudes; see also When/How may I replace the Turn Coordinator with an Artificial Horizon?).