Just my t'penneth worth.........
These mission are still out there to be had, but you must be at least Tycoon to take advantage of the 'BIG' ones. For more high payout smuggling go to Robigo with an ASP, or for high payout cargo missions go to Takurua with a Python.
Good Fuel Scoop is as essential as Oxygen if going to do these mission as you will cross a big belt of none scoopable stars, with fuel getting very low, and additional tank should also be considered, or find a station stop off along the route!
Planning is essential in these mission, and Interdiction's will be like flies around dog pooh! Run or fight, up to you, but be prepared to do either (Or both if you want) Expect to put 4 good hours into this, but you WILL reep the rewards! I am nearing my next goal very rapidly (1 Billion of Credits).
All good points I went for extra tanks and one pit stop in either direction. One by product of the pit stop is by luck I have found three other sites not generally mentioned that spawn lucrative missions as well.
On the interdiction front I don’t seem to get that many although I always have illicit cargo on board. Neither are they particularly lucrative to melt. So these days unless I am interdicted on the way to the station I just submit, boost and jump, saves time as well