Relink Transcoded Media

I'm working on a project with a lot of transcoded media, so when I saw I could now put those files externally I was pretty happy. Unfortunately I haven't gotten it to play nice yet when moving my media to a different drive.

What I'm trying to accomplish:
In general I'm working off of my big Thunderbolt drive, but I'd like to be able to put all my proxies on my smaller Rugged drive for editing on the road. The Rugged drive doesn't fit all my original media.

What I did:
On the Thunderbolt drive I consolidated out, including optimized and proxy files.
I then copied the proxies over to Rugged and using a Hazel rule copied all my audio (that doesn't get transcoded) to Rugged as well (preserving the original file path).
I then unmounted my Thunderbolt drive and opened up FCP. FCP brings up a dialogue saying it can't find my media and asks where to look for it. I point it to the appropriate spot on the Rugged. FCP doesn't relink anything, all clips still red in both Original/Optimized view and Proxy. I select all the audio and relink them manually, FCP finds all the files in the spot it should already be looking.

So: did anyone figure out how to do this correctly?
It's still nice that my Library file is now a lot smaller without the cache and transcoded media, but I really wish I could still use that transcoded media on the road without copying all the original media.

-Ellard