Thats interesting. Did the supplier ask for the feedback or is this an AirwaysNZ product?
The fact that they're asking for constructive feedback would make me think this is not COTS software as feedback for change implies software amendments can be considered, which in turn implies in-house development. (just guessing)
I still think you need to talk to your safety and standards officer together with the senior engineer and find out why the system needs to be rebooted every 3 days. Sounds like the hardware solution is either not fit for purpose or the engineering standards should be reviewed.
For the heads-down time, does it really require more interaction time than paper strips where you have to write and sort the board manually? My study did not see this as a factor once the ATCO learnt how to interact with the HMI efficiently, which shouldn't be more than a matter of a couple of sessions in a simulator.