Actually quite sad to see this, and wish it will be never used. I understand why Devs implemented it, but this method introduces a lot of unspendable outputs and can never be pruned from the blockchain. Kinds of like ' if you don't let me to do this, I have no choice but to do the worse thing.'

Don't think this method cannot be filtered by bitcoin core dev. This is an open source project, any miner can parse counterparty protocol and filter it as easy as us.

BTW, even if we really want to use it, it's slightly better to use PayToPubKey instead. One pub key has 32 bytes, larger than 20 bytes (the size of key hash).