I'm very sure you're right. But that's what I meant when I said that physical reality does not bend to our everyday intuitions. Physics doesn't care whether people think something should be prohibited from working. ;)

> If I get "duplicated" then there are 2 consciousnesses of me.

They're both based on you. There is nothing in principle preventing multiple instances of yourself from existing at the same time. Of course, as already said, those instances diverge over time in the same way that you're not the same person as today when you wake up tomorrow.

>They maybe an illusion, which gets created every moment in time, but it still feels like they exist.

Consciousness doesn't have to be an illusion. It's just the sensation of existing, of being alive, of processing information. It is in a very real sense the feeling of being yourself. There is no contradiction here with the ability to fork it.