This answer states parameters were transmitted in real time.
Thus, why was it needed to record them onboard into (perhaps complex) data recorder that are then jettisoned (with a probability of failure for each ejection)?
I think it should have been easier to either only record onboard on data recorder that are then recovered (like in any aircraft crash, technology already widely used and tested) or either only transmit in real time to ground site (like for any telemetry widely used for orbital launch).