The Unreliable Narrative of the Beforan Ancestors
I don't think the we're supposed to take the Beforan ancestors at face value.
Specifically, I think we're seeing way they're remembered instead of the objective truth, and that the Beforan state is very concerned with its own optics and not as concerned with actual ethics.
Let's go through my interpretations of what some of them say:
Zoologer Coolscar: You don't need to "rescue" childless lusii. If that were the case, they wouldn't be able to manage their children at all. It's either done for PR, an exotic animal exhibit for the wealthy, or they're just weird. This lines up with what we see in Exemplar Danklook; that the higher classes are presented as perfect to the public. Coolscar probably as flawed as the rest of the Amporas, in person. (sorry to the hundreds of Coolscar fans that popped up immediately)
The Helpsman: This is the one that set off this theory. (I thought about the Swansong part first, but didn't expect much deception until this.) Everything about the phrasing is so very very suspicious. He cannot be that happy about this. It feels like they're forcing him to smile for their image and I'm halfway convinced he's still a battery against his will.
The Imposter: Where do I even start with this one, the story is pretty sus. (sorry, I had to) They outline how the different levels of pyrokinesis are tested, and that he landed a job as "extremely weak". But weak means they're there. And if he was tested for pyrokinesis, was the mine explosion a ruse to get him arrested and disappeared for his blood color, once they found out about it? As well, it just casually mentions that the Beforus government covered up his blood, which is quite noteworthy because it confirms that coverups are something they do. What else are they hiding?It's very suspicious how much emphasis they put on ideas like "he insisted he should be a martyr but we made sure to forget him" and "he was just faking it to fit in, no other reason." (paraphrased)
Lamplady Swansong: Have you heard of the serial killer nurse Kristen Gilbert, "Angel of Death"? When I first read Swansong's backstory, I thought it sounded familiar. Gilbert was responsible for hundreds of deaths believed to be "bad luck," when in reality she was manufacturing medical crisis situations in order to show off her skills as a nurse. Sounds a lot like our Vriska with Bec Noir. Of course, Beforan highbloods are expected to look perfect, so if her crimes were ever discovered they would have just been covered up to save face. Swansong may have done some things wrong.
Songbird Sootnose: There's two interpretations here. One, the fact that she felt like she had to hide her disability and keep working reinforces the Helpsman being without a choice in his working situation, and thus the idea of forced hard work under some kind of threat being commonplace. The other, if the Impostor really was framed, was she framed too? Did she ever really lose her sense of smell? Neither is a good look.
The Rankmaid and The Treeaboo: If Beforus really does keep the lower castes working themselves halfway to death while pretending they're happy, it would explain why these two ran off to live in the forest just to hang out and talk about manga. It was an escape, somewhere where they'd never be found. But the Beforan state disavows any connection to the myth of Pupa Pan, and they were just silly weeaboos, so no need to think about that. And if the explosion knocked out the trees, but the explosion was faked (see: the Impostor analysis), was this a deliberate attempt to take down a growing movement against Beforan work conditions?
The Bland Highblood: If you pay close attention, you'll notice that it doesn't say anything about him, personally, at all. Not a word. And this makes perfect sense: He's a mime. He's sworn to silence. If purplebloods are expected to serve as the enforcers of Alternia's cruelty, and Beforan purplebloods are given the solemn duty of silence, then that silence suggests something terrible. That their goal is just as malicious, but they must never tell, sworn to silence in the figurative sense as well as the literal. At minimum, they're the ones responsible for covering up the Impostor's blood color, but likely more.
There is no cruelty on Beforus; the empress forbids it. But the motto is shallow, and they only care that it looks that way.