Should I accept a ship surrendering or should I finish it off?
Sometimes after taking heavy damage an enemy will offer to pay you off if you accept their surrender.
It's possible to deny this and go for the kill, which will also give you a reward. Which option gives you the most benefits?
Solution 1:
Typically, I find I get more consumable items (ie, fuel, missiles, and drone components) from accepting surrender, I get more scrap from destroying them, and a better chance of both (+ other bonuses - crew or weapons, for instance) if I wipe their crew out without destroying the ship.
When considering a surrender offer, I tend to think about the value of the items they are offering in terms of vendor cost to purchase them, and how badly I need items versus scrap. If they are offering 5 drone parts, but I don't have a drone subsystem, I will probably refuse. An offer of 5 missiles, 3 fuel and 20 scrap might be worth it, though.
However, since the values are randomized, so there's really no answer that is going to give you the optimal results 100% of the time.
Solution 2:
If a Mantis ship escapes from battle, sometimes you have the opportunity to trace their warp signature. Their new position will be marked on the map. If you follow them, they will fight again, in a bigger ship. In this battle, they usually surrender, with generous reward.
What a weird mantis.