Also, muted words seem to be very client specific.

I have muted words on Amethyst, but they don't show as muted on Coracle. Instead, I guess I had added a different muted word there. Then Primal shows I have no muted words at all. Same with Damus.

Now I understand that there are plenty of folks out there who only ever use one client, so this isn't an issue for them. They can mute a word on their preferred client and it's all gravy until the next spam attack and they have to add a different word.

That's not the case for users like me, though, who use a wide variety of clients. Read relay selection is a solution that should work with most clients, and it should work against current and most future spam attacks without additional configuration needed.