I find your account of objectivity as “structure preserved across contexts” quite compelling. In particular, the way you separate context-dependence from subjectivity strikes me as exactly right.

That said, there is one question your argument kept pulling me toward as I was reading it: where does that structure—the one that remains coherent across contexts—actually come from?

In other words, rather than taking invariants like velocity relations or conserved quantities as simply given, what are the conditions under which such structures can come to be consistently across different frames?

Lately, I’ve been thinking about this question through a paper that has really captured my attention and hasn’t let go. It doesn’t reject objectivity at all; instead, it focuses on the generative point at which objectivity itself becomes possible. Importantly, this isn’t framed in terms of a conventional observer or conscious subject, but as a kind of generative origin prior to the separation of subject, context, and invariance.

From that perspective, what you describe as “structural facts” appears very close to what the paper treats as a resulting layer. If you’re interested, I think reading it from the angle of “how objectivity becomes possible in the first place” might resonate strongly with your own position.