Thanks for asking! I don’t have a refined write-up. The value of LW, for me at least, is to propose, discuss, and refine ideas still in their infancy or other prepublication stages. Once I have a truly refined write-up of an idea, I think it would be more in the stage of submitting it to an academic journal. However, at that point, related ideas (and interpretation of the journal article)  would be fitting on LW, and the whole cycle could start again. At least, that’s how it is for me. I’m sure other people find different value in LW. 

With that said, for the definition of “encapsulating world,” we would have to start with what I meant by “world.” For that, it’s necessary to look to the literature on the many worlds interpretation. As I’m sure you already know, but just to be thorough, MWI was first proposed in a Princeton thesis paper by Hugh Everett. It’s available several places, but here’s one: https://archive.org/details/TheTheoryOfTheUniversalWaveFunction/mode/2up 

(Hugh Everett, The Theory of the Universal Wave Function, Thesis, Princeton University, (1956, 1973), pp. 1–140.)  

Of course there’s also the book by David Wallace, which thoroughly explains the idea of a "world" in this context:  (Wallace, David (2012). The Emergent Multiverse: Quantum Theory According to the Everett Interpretation. Oxford University Press. ISBN 978-0-19-954696-1).

Also, I just came across this article from 2009. The permanent link is at https://doi.org/10.1016/j.shpsb.2008.10.002. 

(Stefano Osnaghi, Fábio Freitas, Olival Freire, The origin of the Everettian heresy, Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, Volume 40, Issue 2, 2009, Pages 97-123, ISSN 1355-2198,https://doi.org/10.1016/j.shpsb.2008.10.002). 

A tangential point about this article is that it reflects a point that I (poorly) tried to make in an earlier post, which is that there is a subset within the physics community that seems almost theocratic in the way its members regard physicists with differing (more philosophical) viewpoints.  My post made a very unfavorable impression upon some LW folks, as they promptly let me know in the comments, and afterward I conceded that “theocratic” was too strong a word. I also recognized that any misunderstandings were my own fault for obviously doing a poor job explaining myself. Oddly enough, the article I just cited is full of theological-type terminology to describe the same phenomenon I tried to describe. That doesn’t justify my original post. However, it does seem to add to the wry, winking irony of the universe.     

As far as the “encapsulating” part of an encapsulating world interpretation, you could always check out David Chalmers’ descriptions of how quantum mechanics might be viewed as part of simulated universe. (Chalmers, D. J., & Peacock, T. (2022). Reality+: Virtual worlds and the problems of philosophy. W. W. Norton & Company.) I would give you page numbers, as the book relates to quantum mechanics, but there are many references throughout the book. You could always look in the index to read all of them.) In this case, the “encapsulating” world would be the simulator/programmer/external world.) However, in my own “bare bones” view, I’m not including any of the other assumptions that would go into the simulation hypothesis (such as the idea that the encapsulating world consists of programmers, or even the idea that there are any intentions involved). 

I apologize for not giving a single sentence definition of “encapsulating world” when it comes to an encapsulating world interpretation of wave function collapse, but it’s the type of concept that requires the mathematics and diagrams of the many worlds interpretation, along with a view of quantum mechanics similar to what Chalmers describes, and then refinements from there. 
 

As I mentioned in the original post, although the idea independently occurred to me that wave function collapse could be explained by an encapsulating world interpretation, I’m sure it occurred to millions of other people before it occurred to me. Although the idea is not unique to me, I posted it because I still think it would be worth discussing and refining on LW. 

Hopefully, the discussion can be at least partially collaborative. I’m starting to realize that LW users are mostly male, and I wonder if this makes discussions slightly more competitive than collaborative (i.e. - some people seem to want to “win debates” a bit more than collaborate). I’m not saying this trend is good or bad, but I’d really appreciate some constructive, collaborative insights, in addition to critiques. (Granted, I recognize that any negative criticism is probably my own fault for poor logic or poorly-worded posts that lead to misunderstandings. Moreover, negative criticism can definitely provide room for growth. Nevertheless, a few collaborative insights that hadn't previously occurred to me would be a much-appreciated supplement.) If you’ve read this far, thank you!