I think the concept is a very interesting one. The slow buildup of procedures and literature does a great job of making it seem as though the therapist is going to be interfacing with an individual sapient person, such as a reality bender. The reveal in the procedure was, for me, a chuckle-inducing surprise. As far as clinical tone and structure, the draft looks to be in good shape to me. It'd technically get tagged "tale" since it's not an SCP, but in-universe it's more of a supplementary procedural document.
However, I feel that the article is missing something in its current format. An introduction might work, but also spoil the surprise. Maybe a "Background" section after the Procedure? Knowing the general theory of the procedure is good, but I think its implied narrative needs to be developed more to be really satisfying. To that end, here are some questions that came to mind for me:
Does the pseudo-malignant madness at the fringe of all existence have an SCP designation? If so, is this a part of its containment procedure, or an experiment which might be incorporated into its containment procedure if successful?
How does the Foundation know whether this worked, or to what extent if so?
What series of events or line of research led the Foundation to conclude that this would be a good idea?
How come Amazonian shamanism? There's like, umpteen different shamanic traditions for every historical population on the planet. So if one particular Native Amazonian tribe happened to get the approach to this anomaly exactly right, the Foundation had to have figured that out somehow.
What is the crawling chaos from beyond the edge of time like as a patient? Are they intense, grumpy, surly and withdrawn — or does that vary? Presumably the psych screening tests, in addition to ensuring the therapist's general competence and stability, also screen for the mind types which have the optimum potential success rate.
UNRELATED: I also took the opportunity to snoop around your sandbox a bit. It's nice to see someone who, like me, has a gazillion different tabs in various stages of development. I think I'd seen the thread title "The Mountains of Minty Freshness" wending its way through this forum, but I hadn't actually read it until now.
And OMG T_T I love that concept. Love. Eldritch entities invading our reality because they crave tasty peppermint cakes? An improper P&L graph representation of the cake company's financials might empower more Shoggoth to make an unexpected surprise appearance in the transantarctic mountains to pursue their quest for cakes? Everything about this is tailor made to tickle my fancy. I'd want to see the Foundation front company that buys the cake factory have the initials SCP — it's a thing some authors do which I always find amusing — but that's totally optional. Another totally optional suggestion: if these entities have been around for awhile, they might have been documented in the past by the Antarctic Empire.