The rules suggested here are much too complicated. A much easier solution would be: abandon only works within a 15 km range around a space station.
This gives everybody who wants to do a legal transfer enough working area, but prevents abuse for piracy. At the same time it would be easy enough to implement and if you want to reason why it is like that: legal transfer has to be certified, to do that you have to be in registration range and thus within sensor range of a station, which is allowed to certify the transfer.![]()
...or... Make "Abandon" what happens when you dock ships - https://forums.frontier.co.uk/showthread.php?t=238907