Bi-amping with Audioquest cables

Owners of Audioquest hyperlitz cables will know that these cables are made up of multi-strand wires, which are individually insulated. This makes the job of bi-wiring more effective and quite straight-forward. In spite of this, Audioquest have told me that they should not be used for bi-amping (ie two pairs of bass and treble wires at both speaker and Amp ends,)but instead, I should use TWO pairs of cables. Nevertheless, before I was advised of this, I had in fact configured a single pair of their Indigo cables into a a bi-amp set up and still use them like this to this day with good effect. I have now managed to pick up a pair of their Moonlight cables which are currently single wired and am considering re-wiring them the same as the Indigo's. Does anyone know why I shouldn't be doing this? Could this cause problems with Impedence?(I have emailed Audioquest but to date not had a reply).