Simple and straightforward, the number one reason that I do not use repair guns is their weight. 2400 kg is heavier than a gat turret, which is just rude. If it is going to be that heavy, it ought to at least have some of the tracking. However, as an alternative:

The mkII requires the second mentor badge and all, so players have to earn it.. why not make it half the weight or so? Maybe 3/4ths? 1800 kg is still a hefty handicap for anyone flying it.