Well that conclusion is certainly a reasonable enough possibility, however.....
I think you misunderstand a few things. “To me” the Beale mystery revolves around two different perspectives, the first being that the narration, in some form, is a work of fiction. The second being that the narration was possibly designed around some actual event concerning real wealth.
Obviously, the fiction perspective is indeed the strongest regardless how it was designed or it's possible purpose. And, if it is any form of fiction then there is no need whatsoever to pursue it any further as fiction theories relating to the narration are, as you know, a dime a dozen and far too easy to propose by the simple fact that there is little existing evidence of it being anything else. So why waist one's time trying to solve fiction?
On the other hand, however, the second perspective, that it might be a narration in relation to some other actual event, isn't nearly so easy to propose or to provide, and for obvious reasons. But here's the thing, these second perspectives have to be eliminated before any fiction theory can be fully embraced. So here's the deal, “try as I do, I can't dislodge the theory that I keep tossing at you.” And in fact, the more I try the stronger that theory continues to grow.
My point is this, I don't care if the narration holds some measure of truth or if it is a work of fiction, I just want to know for sure that it is indeed one or the other. As I said a moment ago, it is far easier to establish any form of fiction theory as long as there is nothing else to stand in the way, however, and very clearly, the current second perspective is clearly standing in the way and there exist more then enough evidence to support the notion that men "may have" actually transported the wealth described in the narration. So until this possibility is eliminated then any form of fiction theory, regardless of its nature, can't be fully embraced.
In the current theory we have the same dates, the same wealth, a second publication - regardless how precarious or suspect it might be, that further supports all of it, and we also have the personal testimony and charges of D'Onis that further declares that all of it was indeed taking place. “So this is my personal issue” in all of this Beale conundrum, a theory that despite all efforts to do so, I still can't get off of the table.
If the narration is some form of fiction then we can easily, very easily, construct an endless stream of seemingly reasonable remedies/solutions as to how that narration was formed, what the ciphers contain, and why. But if that narration indeed contains a measure of truth to an actual event, well, not quite so easy to construct a reasonable remedy/solution because we can't be so free with our selective picking and choosing. Instead, this second perspective has to be spot on, dead to rights accurate. Not so with anything proposing fiction, or any form of it, because in this later there is nothing that needs to stand as spot on, dead to rights, accurate. Much, much, much easier and far more convenient when going the fiction route, any form of fiction route. But can that selective fiction be fully embraced? No, not until all other reasonable possibilities are off of the table, and quite clearly, they are not yet off of the table. And in fact, quite the opposite.
But for sure, as Franklin noted, one area that lacks any supporting detail is the absence of any actual evidence of the alleged travels.
PS: And I have no idea why each time I save a post it automatically adds double spacing to all of my paragraphs?