Well done, Xav. I’m positive I’d have beaten you to it had OWF been working last night.
I’ve never heard of any explicitly deleted sections of the Stockyards. Although screenshots do show parts with Paramites in them, it seems like they were replaced by Scrabs. There are undoubtedly such deleted paths that went through to various stages of design, construction and testing before it was deemed better they be excluded from the final build, but I don’t think any accessible in the final game. Not with noclip, at least. I’ve gone off every edge of every screen, I would have noticed a wholly new area.
There must be all sorts of areas in RuptureFarms that we didn’t see in the game, but that’s not to say they were ever designed to be included. There is one such section I know of, the ‘Cell Condo Silo’ where Mudokons sleep. There is production artwork of this place by Steven Olds in the Art Book and by Raymond Swanland on OddBlog. It looks like it will make an appearance in the Abe film.