> You could integrate acceleration to get speed - the flight is short enough to make compounding errors easy to ignore.

‘Easy to ignore’ is not a term I would use here, especially given the motion environment of a rocket. It seems like it might be beginning to be borderline possible.

> You could integrate acceleration to get speed - the flight is short enough to make compounding errors easy to ignore.

False, given how noisy MEMS IMUs are, and the accuracy required. Even Ring Laser Gyros drift quickly.