Also there's a book by Stephen Baxter set in his Xeelee universe which takes this premise for the cult mentality of a terrorist cell

Sorry this doesn't really add anything, just thought it kinda funny

Yes, the problem with quantum mechanics is it's not just your Deepak Chopras of the world that get sucked into quantum woo, but even a lot of respectable academics with serious credentials, thus giving credence to these ideas. Quantum mechanics is a context-dependent theory, the properties of systems are context variant. It is not observer-dependent. The observer just occupies their own unique context and since it is context-dependent, they have to describe things from their own context.

It is kind of like velocity in Galilean relativity, you have to take into account reference frame. Two observers in Galilean relativity could disagree on certain things, such as the velocity of an object but the disagreement is not "confusing" because if you understand relativity, you'd know it's just a difference in reference frame. Nothing important about "observers" here.

I do not understand what is with so many academics in fully understanding that properties of systems can be variant under different reference frames in special relativity, but when it comes to quantum mechanics their heads explode trying to interpret the contextual nature of it and resort to silly claims like saying it proves some fundamental role for the conscious observer. All it shows is that the properties of systems are context variant. There is nothing else.

Once you accept that, then everything else follows. All of the unintuitive aspects of quantum mechanics disappear, you do not need to posit systems in two places at once, some special role for observers, a multiverse, nonlocality, hidden variables, nothing. All the "paradoxes" disappear if you just accept the context variance of the states of systems.