10-15 years ago I came across Spamcop and was impressed and inspired to see folks dedicate time, skill and effort to combat spam.
After a recent bombardment with spam of a very primitive nature, just our of curiosity, I googled "spamcop" and was totally floored to see that it is still up and running!
Is it still actively managed? - If so, THANK YOU whoever makes that happen!!!
The only thing I would suggest is to give the site a facelift and make it more user friendly, but I totally understand your focus is not the UI/UX - but rather, the effective suppression of spam.
Best regards, in gratitude,
Pedro