We're going off course!
I'm going to make myself unpopular, and a potential future laughing stock, here and nail my colours to the mast: I don't think the answer to the UA will be solved with Mayan numerology, Hafnium, Painite, SAP8s, Trinkets or any other weird and wonderful stuff. It's just far too woolly. 'Oo it's a nav computer or an engine, so this other thing must be the fuel', etc etc (not taking the mickey, just paraphrasing).
A bunch of canisters rattling around in a cargo hold, or floating in free space, do not a ship, or key, make! Do we somehow think that these items are going to transform in front of our very eyes like Optimus Prime?
If the UA is Thargoid, then it acting as a permit to a Thargoid system is believable.
It and SAP8s, and all the rest, being in the hold triggering something (when these mysterious substances are in shielded canisters except the UA itself?) doesn't make sense - except if it brings about a pirate interdiction.
I don't think it's going to 'do' anything monumental at all - certainly not produce a Thargoid interdiction (the assets would probably have been found in the game files by those that do this kind of thing by now), but I do think the answer is out there at the moment to discover its origins and to find a place of interest.
Take it back to the beginning, people: we were told to listen, not study its legs or pair it with other exotic cargo (some of which didn't exist when the UA was introduced, remember).
We got Morse.
We need to find any discrepancies in this Morse, any additions, anything that doesn't match up we've what we've learnt. It's the only repetitive behaviour that, once it was studied a reasonable amount, (to be fair, too, less than many other attributes of this thing) actually provided any information.
A change in this behaviour would provide more information. Why it's doing it is almost less important: there are an infinite number of ways to make '5' - and I think all these theories are effectively proposing '2+2' as one of them.
Everything else we've been looking at or listening to so far has yielded nothing except more wooliness. I love the Mayan number theory - but to be honest, that's not solvable 'in-game' is it, unless the game is being played by academics in the field of Mayan study?
More importantly, we've got at least 6 different ways of reading the numbers! So how are you supposed to know when you've got the right number!?
Same is true for all the cargo combinations: Tried it with some copper, gold, frankincense and myrrh? *that* might do something, too! How many combinations must we go through, considering the total number of different types of cargo there is? We can't brute-force this - it needs to be reason.
This isn't to belittle or insult anyone that's come up with or taken part in these theories. I have, too, lots of times.
But I'm looking at it right now and thinking we're back to taking the audio, speeding it up and trying to find 'redrum' in a spectrograph of the recording (not actually done, just illustrative purposes!).
I'm nearly done...
I think the UA is singing the song by the Urban Cookie Collective, but with the last word changed: 'I've got the key, I've got the secret - I've got the key to another race'.
The Morse was the key (and we were told to listen) - so what is the secret that it betrays?
(Ducks and runs)