Looking at the information posted since the 3.2 update, I would guess that they adjusted the algorithm to require more favor to get the higher value drops. At the same time, they introduced a new tier of parts that has higher stats. Forecastle is key for Favour and Aftcastle is key for Retrieval. Using higher values of those components results in reduced speed and range, which makes the trips take longer. By doing all of the above, SE are slowing down how fast people can collect high value drops, which balances out the increase in the value of those drops (addition of tier V and IV spoil).

So, slow, high favour builds seem to be the choice for farming now?