Filtering still works because now it isn't just on the post body but on all the note fields like profile pic, Display name etc at least on amethyst.
Discussion
It would obviously be a combination of different solutions to fully combat spam but for client side, filtering (with regex support) is a low effort solution that seems to work well
nostr:npub17as80dy9dpapt3jmu8rr9dm34ymzzg7p08v8dnu540h66l43m3vq9jde6v will probably generate a new key and profile for each spam message next