The first free floater UA was found in HR 1185 (Xbox player!): VERY CLOSE TO MEROPE.
That's why I've always thought they STARTED from Merope, and then expanded.
They were deployed in Merope, to start a search.
Rizal, size wise, what end of the UP matches the end of the UA? The large one or the small one? Could the UP be the "deployable" version of the UA? Once at it's destination one end opens up and looks like the UA at that point.
Maybe the audio instructions aren't for us, but instructions for the UP/UA. "Go make a shell, monitor, report back."
Also isn't there a specific type of system the UA's are found in. In looking for them in the 135-150 range don't they only show up in systems with metal rich landable worlds? Isnt that the same criteria as barnacle worlds? Could they be looking for "barnacle habital worlds" and deployed as "here's one".
Going off the rails here: Weren't these things said to be "genetically engineered". Barnacles take in metals and produce meta-alloys. Probes/UAs find other suitable worlds for "barnacle factories". It's a colonizing technique. Aliens come later and have all the material they need for construction.