Maybe a good way to achieve this is to create a new AbstractArray type (say, ComplexArray) and overload it, which is more standard Julia practice.
To get the simd tricks going, overloading broadcast and direct it to a new set of arithmetic operations.
This idea is still needs development.
And even more on-point, is to look at Images package and how it handles images stored by pixels vs. by color-channel planes. This is highly analogous to the real/imaginary part of complex variables, and Images package has had a lot of effort put into it.
But… can’t you use StructArrays as they are? What’s missing there?
What I want is tuple, not array.