If you do "Scrum, exactly", then when things don't quite work out, being "on your own" is the best case scenario. Worst case is that someone yells at you and blames you because Scrum Objectively Works so it must be your fault.
I see no reason to believe that Scrum is a tightly tuned machine that must be precisely run to work at all, and any deviation from it makes it fall apart. In fact, if that is the case for Scrum I'd consider it a fatal objection. I don't believe the effectiveness landscape for project management techniques is shaped like that, I don't believe that the effectiveness landscape is a black pit everywhere just around Scrum only for a sudden spike of effectiveness to exist precisely where Scrum is located, and if it were shaped like that, I don't believe in the capability of anyone to have found and proved that spike. Since the only practical algorithm to explore this landscape is gradient descent, anyone carefully and thoughtfully exploring this landscape should never have found Scrum.
Or, to put it in less mathematical language, the idea that Scrum is super effective but if you deviate from it just a bit it all falls apart is complete garbage.
Do real agile, all the time. Scrum's only useful for raiding for ideas, and I'm not particularly impressed with it for that purpose, either. But it's not quite literally bereft of good ideas. I wouldn't give its ideas any particular credence for coming from "Scrum!", through. I don't see a lot of evidence that it is specially deserving of respect. It seems to work for some people, yes, I don't deny that, but the rate at which it works for people is sufficiently low that I don't think it has any sort of special claim.