Often enough I get missions with low profit which I stack to make the trip worth. When I arrive in the system I get "... we got a better offer in XYZ, deliver the goods there....". At this moment all I can do is acknowledge the detour and go wherever they want me to go - if I'm allowed to do so at all. Currently I do not have the option to say "no thanks - I stick to the original plan and location". This option is what I'm looking for. Especially when the detour is on e.g. Lave 2 where I do not have a permit for, or the value of the mission is too low.
All I can do now is dump the goods and get fined for not completing the mission(s).
All I can do now is dump the goods and get fined for not completing the mission(s).