Actually, I was testing this last night. When you dump the UA from the hold, it tumbles & spins for a bit, getting slower & slower until it stops & holds a fixed position in space. What's weird is that that's different behavior than when I jettisoned the Soontill Relic cannister from my hold in Soontill (https://www.youtube.com/watch?v=eQ-T7590WeA). Unfortunately, I tried repeated drops in the same place to see if it was pointing the same way (compass needle) & it does not. It does seem to stop rotating though.
Well this at least definitely proves that it isn't just some random object, but a "ship" or "drone" along the lines of a navbeacon, which is specifically designed to float in space and hold its position.
While we "knew" this for a while already, there is still a fine line between assuming and having evidence, and this would be some evidence to back this up. Maybe underwhelming, but still something.