I'm not sure yuou understand the importance of retaining the GPS/Data Logger
These are essential these days to prove that a flight took place for competition or record purposes.
On the few days that a 500k, 750k or 1000k flight takes place in the UK or during a rated competition you need absolute evidence that the flight conformed with the regulations
To ask a glider pilot in such circumstances to give up the GPS/data logger combination would be like asking the Red Arrows to stop a flight to let a microlight pass through the display area