At last, after roughly a month and a half, a new goiardi release has hit pre-release status. This releases introduces "shovey", a way to execute jobs on nodes without a full chef run. It's documented in the README at https://github.com/ctdk/goiardi/tree/serfing#shovey.
This pre-release is especially important for shaking out any bugs that might be creeping around, so if you're so inclined please take it for a spin and see what falls off.