I cannot edit my original post any more, but a helpful HNer "DesolationJones" was able to provide a little bit more insight into Comma's safety strategy using information trawled from Reddit comments and Medium posts: https://news.ycombinator.com/item?id=26158158 .

It seems that Comma are actively working on documenting their safety systems (via a new hire to own this task) and creating an audited checklist. And, there is a "new vehicle" checklist enumerated in a Medium post including some safety constraints, although in reading the Panda "safety" tree, I found no actual acknowledgement that these specific constraints were audited for each vehicle addition.

So, it seems that the great strides since 2018 continue - once these promises come true, they will have almost reached what I would consider the baseline level for a safety-related automotive system. Perhaps they will be able to secure an exit this way - I am actually rather surprised they haven't, given the froth level in this space as well as the valuable training data they have collected from their users.