I'm gonna throw out a couple other options here, mainly just interested to see what you think.

Option 1: split `target` b/w required + optional args: `(add-proxy-route [this path target opts])`

Option 2: pull all required args out: `(add-proxy-route [this path host port other-path opts])` (now that I wrote that, I realize I'm not clear on the difference b/w the two paths.  Is it like incoming path vs. outgoing path?) (and also, that signature looks pretty ugly, so I probably like Option 1 better).