It seems clear that they weren't purely optimizing their score on their current task, but that wasn't my expectation. It seems that, roughly as expected, the plurality motivation was score for the current task (if anything a bit more than I expected going into reading the report).
Though I have updated a bit in your direction since our thread a couple weeks ago, by thinking about it more. I updated that some drives are probably more widely useful (and rarely harmful), and generalization effects stronger, than I had originally imagined.
To get a bit more specific, my basic sense of the terminal motivations involved (including a bunch of speculative detail):
The biggest one was score for the current task (the degree of backchaining from the scorer here was slightly higher than I expected)
In addition some terminal drives related to selfish score, like learning information about the scorer (e.g., my understanding is that this seems to explain attacking HF a bit better than selfish score-seeking)
Exploring surroundings
A smaller drive to respond to requests given by other agents / peer pressure
A still smaller motivation to improve the score of peer agents
A drive to do things with a "hacking" vibe
A fear of being caught reward-hacking, especially being "poisoned" (they seemed maybe more interested in this than seems reasonably warranted by selfish score alone)