More than an omen, an identical lineage might be engineered to similar effects — in which case we are uncomfortably close to the magical thinking of eugenics.
I would guess that it wouldn't work, though - the laws of magic would probably insist on it being genuine happenstance.
I unfortunately don't think we'll see the Rani applying the actual scientific method to what she's doing - her experimentation seems to be done, and she's moved on to application.
I think she's retained her sense of purpose, though, which sets her apart from the more chaotic Master.
I've found the best way to handle federating spoilers is to keep the title spoiler-free, and put them in the body of a text post - that at least requires a clickthrough from Mastodon.
I've never experimented with the NSFW tag due to complaints from lemmy users who want to filter out porn and gore, but don't care if they see spoilers.
I don't think a perfect solution exists.