I could live with a feature where each one could set the limit themselves.
But this should also be incorporated when trying to send a memo to someone. It should inform me what the threshold of the recipient is. For sure if the steem or SP will be burned.
I don’t have so much Spam in my wallet, I am just not important enough 😂
For me it is just free steem. But I do understand if you get lots of them that it can become really annoying!
So I am not annoyed yet by it but I do like your idea!