So...

Convoy's rewards got a boost - worst case scenario is 25 to 50 per days, which is quite balanced compared to the 40 to 120 coupons plunderers get. It sure beats the current ratio of 15 to 50/150. Also, chance for convoys to run SS twice per day. This could push more ppl to do convoys.

Plunder got nerfed - duh! The cost for SS plunder makes sense, it's not fair for convoys to cost ingots for extra attempt while plunders can do it for free. Plunder also need to prioritise which convoy to hit: Extra SS needs tickets, but free tickets drop at S or A class only. So unless they have the ingots to spare, they have to go after an S class or A class, which will cost them their plunder attempt of that day. If plundering fail ppl get a refund, a plunder ticket which allow them one more free attempt.

Another thing is that ppl can do both plunder and convoy. So mid-game players have more options to choose during the event.

Overall, a more balanced system that lessens the gap between convoy and plunder. Hopefully I'll get to try this system out at least once before the game kick the bucket.