Excellent post
BIGBATMAN 
So they (BAA/BA) have bought into the technology and are not allowing it to be used to its best advantage.
The TRM should inspect the stand and ensure the stand is empty for the aircraft.
But the technology is (apparently) capable of automatically scanning for obstacles? And there are still 4 Mk1 eyeballs in the cockpit.
Quite often a TRM will put in the system B767-200 instead of B767-300 thinking it wont make a difference but it does the computer has a set of aircraft size parameters and a wrong type will fail the system.
The Safegate can be remotely programmed, so why not let the person allocating a/c to stand pre-program it, thereby removing the need for the TRM to manually enter the data?