You can always fly at risk.
1) Do the exploration trip unpledged.
2) Return to bubble and swap to a heavy combat ship
3) Do powerplay to rank 5
4) Sell Data
5) Profit
I did that on my 8 month trip for bragging rights and got 500mil extra bonus on my 250mil of data for a 750mil total profits.
https://forums.frontier.co.uk/showthread.php/281395-8-months-559-000Ly-and-a-monster-of-a-thread
Bear in mind by doing the cargo transfer route (safer than combat route) to get ranked up in powerplay I spent 100mil credits, I get 55.5mil of that back from the powerplay salary in the following weeks but its still money you need to have before starting.
So overall I spent 44.5mil to get the 500mil bonus.
This up-front cost to rank up basically means the more data you have the more profitable it is.
Anyway, in the combat conda I flew for powerplay bit:
https://coriolis.io/outfit/anaconda...f050504040403030324.AwRj4yuqg===.EwBj4yuyEYg=
Over the 25 trips (2 jumps out, 1 jump returning) each time carrying 400T of cargo I got a grand total of 5 interdiction attempts. 4 of the I avoided in supercruise before the tether was established. The final one followed me into the station and got turned to flying scrap by the police and station guns. I had expected it to be much more treacherous but it was quite mundane actually.
If anyone wants more details and/or guidance ask away or fire me a PM an I'll walk them through what/how I did it. It should be fairly obvious from this post though...