Ilya, I'm very interested in discussing this further with you. I have a reasonable idea and implementation of how I would want the generic n-dimensional types in D to work, but you seem to have more experience with BLAS and LAPACK than me* and of course interfacing with them is critical.*I rarely interact with them directly.
I have created Phobos PR. Now we can discuss it at GitHub. https://github.com/D-Programming-Language/phobos/pull/3397