That would be more straightforward (and fast) to simply send the whole transformation matrix :
shapes cubes foo 0.234 1.000 ...
Yes, as Frank has said, I am using OSC this way. Vectors are sent as three arguments in a message. Actually I recently had a discussion about this... one opinion was that it should support both 3-argument vectors as well as the /x /y /z messages, so that it can be easily mapped to particular variables... Of course, in that case you'll also want to support /magnitude and /phi, etc.... ;-) Many many options here. And that's not even counting how to support units.
Anyways, yes I'll be talking about this at NIME. Should be fun. ;-) Also hopefully I'll also present it or have a poster at the Pd convention.
In fact I didn't want to mention it on the list because there are still quite a few bugs in the software, and I wanted to wait until the convention to discuss it, but since it pertained directly to your question....
Steve