There's a monster in our house, and I think we're feeding it:
So Obsidian Orbital recently started deteriorated, right? Much like the other stations we've sold UAs at. And like our ships when we have a UA too.
But giving it Meta-Alloys stopped the problems. So we've got to ask: why? What properties do the MAs have that stopped the problems. Surely we didn't use them to patch up the issues, we barely know what MA is, nevermind what the problems were, and even if we did how EXACTLY did MAs solve the issue anyway?
You know what I think? I think we simply distracted the problem by feeding it its favourite meal.
So let's work from the beginning.
The Barnacles are a growing outpost, sent by a race that's from LMC. They put their galactic symbol on it like we put our Solar system on our probes, only they sent these things to an entire other galaxy, not just to a local system, so what would be the point of putting their home-star on there, we wouldn't be able to cross reference and identify it. So they put the next best thing. Their galaxy.
These things are designed to draw out metals from the planets they're on and convert them into Meta Alloys, the chosen building blocks for the alien race we see. At the same time, they dispatch the Unknown Artefacts to disperse from the primary barnacle location to begin drawing out a border; the outer edge of a bubble territory they are planning to use and exploit when the outposts are finished growing. They don't fully expect to find sentient life, but the UAs are designed to report back any information that they find on their travels just in case, such as the local language used (mistakenly learned as morse from the loudest most predictable signals in the system: the nav beacons), the names the locals have given to the systems if there is one (which would also serve the purpose of showing the newcomers about any potential opposing territories and its subsequent size), and if necessary, the specs of the local life and their vehicles (the recent morse pictures of our ships (note this is likely only in morse so WE could see it as players, in game its likely to be sent back in the language of the newcomers, but how would we then see what they were doing?)).
These UAs are also spreading more barnacles to lay down a solid foundation for the newcomers so when they come out of witch space or whatever space they are using to haul ass from one galaxy to another, there is already home comforts and a firm foothold for them to begin their expansion across the milky way. After all, why would they move from one galaxy to another if it wasn't for more resources? Have they consumed all of theirs already and are now after a nice ripe Milky Way?
So the Barnacles launch the UAs from Merope mainly. The ones we find have been interrupted mid-travel, so when we find them they point themselves AWAY, not towards, where they've come from. And when they 'expire', that FSD like jump is them re-entering their travel? Maybe, either way, the important thing is we sell them to stations, and they now have exactly what they were looking for: high metal content! Well, not quite a planetary version, but metals galore none-the-less. So they begin entering their Barnacle stage of life, consuming metal and converting it into Meta-Alloys.
Eating a station is going to do bad stuff to it, right? So we see the problems arising. The stations are being consumed. We know Meta-Alloys 'cure' the problem, but how? Do we just 'patch up' holes with it? The station wasn't made of MA in the first place, how exactly is that going to help?
Well, what if it's not fixing the problem as much as it is now feeding the UA/Station Barnacles with the MA it needs to begin the next stage of its life: reproduction into more UAs. At that point, it's going to use the MA as food, not the station, which essentially makes the problem SEEM fixed.
But it's not fixed. There's still the problem of the UA/Barnacle growing within our stations. Within our bubble.
I think they're coming guys, and we're helping build their bases by giving them ours.
TL;DR? There's a monster eating the walls of our house, so we've fed it something else that it likes. That stops the monster from eating our house, but it doesn't stop the monster growing.