Seems Jump Drives are either bugged or got a slight unannounced modification. They seem to have had their accuracy reduced significantly.
Testing on a set of coords that normally put the jump ship 7-10k off the initial survey point has now put them jump ship anywhere from 30k to 100k off the initial survey point. This is using a mark 4 drive with coords from a mark 3 scanner.
Perhaps some first steps in balancing jump trading, who knows.