A lot of POB owners in the past have had issues with restricting illegal cargo. IE a base tries to sell black market munitions, then a KSP docks sees it and tries to punish for it.
The ability to restrict who can see / buy commodities would be nice. The two ways I can think of to do this are to add a new password type to the base that only allows the person to login to buy restricted commodities.
The other way would be to simply use the docking list and allow those people to buy the hidden commodities, though the other option would be more useful.
I came into conclusion that one additional FLHook command would be very useful: ability to /sendcash to the highlighted target, instead of writing entire name. It would speed up the entire process of paying to the escort and pirates.