We have been warned in our CSM training: "Scrum’s roles, events, artifacts, and rules are immutable and although implementing only parts of Scrum is possible, the result is not Scrum." - any deviation from Scrum leads to a dangerous "Scrum-But" - or worse ... so, you should stick to Scrum as per Guide!
Is that even a problem? Forget it!
Why would we even care if "the result is not Scrum"?
Here are a few examples of "results that aren't Scrum" ...
Unless you are in the business of producing and selling Scrum - why would it even be a problem if "the result is not Scrum"!
Scrum is but one of many means of achieving better business outcomes. It is neither a desirable outcome, nor the focus of your attention - again, unless you're making your money from Scrum.
As agnostic agile practitioners, we aren't forced to sell Scrum. We're trying to help our clients achieve better relevant business outcomes - more sales, more revenue, new markets, happier customers. If Scrum helps us get there, we're happy with Scrum as far as it helps. When Scrum becomes a distraction or an impediment - we'll gladly throw Scrum as per Guide overboard and do something else that works.
"If you deviate, the result is not Scrum!" is a kind of fearmongering that only works on those who don't know that there are other, equally valid approaches. There's plenty of them around.