Not documenting, but tracking in that spam attacks are both more visible when aggregating relay data, but also potentially more bursty and annoying too.
I’ve got content based spam down to effectively 0 using ML. Just like email spam, some will slip through, but it’s pretty decent and can improve as we scale. I open sourced the training data and code - but I have an update yet to release. Obviously it has limits tho.
This attack is kind of new. It’s more just boating DBs and clogging any relay processing. And events without content, are harder to evaluate without touching the DB to query for state - I have stateless validation works at present.