It would result in 24*60=1440 unused byte in RAM and it also would need a more complex function for sending the entire array to a python-script (which expects a single sensordata in a length of three byte).
I think packing will make access to your array of structures less efficient for the ESP8266. This is because members of some array elements will likely span 32-bit word boundaries. But, if memory use is more important in your application than processor cycles, then it should be OK.