@dignifiedquire and I went over this, and I believe it now clears the bitmask correctly (and in correct place). This is consistent with the observation that original code (no clearing) was slowest, but first attempted fix was much faster but failed tests. Given that we also have an understanding of the original transcription error that led to the original code, I'm pretty confident in this iteration.

Nevertheless, especially since we've been bitten once, we should make sure this code is tested at least as much as the first attempted fix was. Remember, the discovered test failures were non-deterministic and not expected to always manifest. We need to test this enough times to have reasonable expectation that any failures introduced will have showed up. If we see any such failures, we need to take them seriously (as we did with the previous).

Even though I'm more confident in this than I was in the previous, I'm blocking merging here until I hear that we have successfully tested this (as thoroughly as we eventually did the previous). The reason I am requesting changes rather than approving with 'conditions' is that the latter approach didn't prevent the code from being merged last time. So this is a slight process adjustment based on what we learned in the last round: we need a bit of extra diligence here.

Ran the small lifecycle tests looped overnight without issue. This is where the failure showed up both on CI and on my machine in the past.

Based on @cryptonemo's testing — which he believes is sufficient to have caught the previous error but uncovered no problems here — I am approving this now.