I started to review it. I will need more time to digest everything, but in the meantime I'll share one of the findings from my local agent:

Before, `_apply_goodtimes_filters` only runs when all 9 datasets are present,
so Filter 1 always got 9 datasets. Now, if 6 or more of the 8 surrounding pointings
are unmatched, Filter 1 raises, failing the whole job. Whether this is a realistic
outcome or not needs to be checked, but it could happen to matched pointings
near the switchover.

I started to review it. I will need more time to digest everything, but in the meantime I'll share one of the findings from my local agent:

Before, `_apply_goodtimes_filters` only runs when all 9 datasets are present,
so Filter 1 always got 9 datasets. Now, if 6 or more of the 8 surrounding pointings
are unmatched, Filter 1 raises, failing the whole job. Whether this is a realistic
outcome or not needs to be checked, but it could happen to matched pointings
near the switchover.

There should almost never be an unmatched pointing. I believe there is one to date that occurred on the pointing where the gain configuration of Hi was updated during the uplink contact. In general though, a unmatched pointing will be rare and only caused by live commanding or an anomaly. Raising in this situation is the appropriate thing to do.

I have only one non-blocking comment/question: the new code refactored the calculation of hv_deltas as the _get_gain_match_values() function. I like this, but from the diff it seems like we went from performing the operation once in mark_unmatched_gain_config() to three times [added work is now in _add_qualified_event_masks() and mark_overflow_packets()]. I just wanted to bring this up to double check that this small amount additional work is indeed intended, or if we would prefer to just pass the single result around.

Yeah, I see what you mean. Really only two of these are duplicated work because the _add_qualified_event_masks() function gets applied to each of the 9 pointings of l1b_de product input. Although it would be possible to store these values, the amount of duplicated work is tiny (retrieving 4 attribute values and filtering a small dataframe) and the tradeoff for keeping the function signatures simpler is, IMO, better in this case.