Question re tri-wiring

I just bought a used pair of speakers that take tri-wiring (Avalon Ascent II) and only have a pair of Cardas Golden Cross bi-wire cables. Would it make any significant difference if I were to run a different pair of cables, say, Cardas Neutral Reference, as the third wire in the tri-wire configuration, as opposed to using all Golden Cross? Also, I can pick up a pair of Neutral Reference bi-wire for a good price and could run them on the tweeter and midrange and then use the Golden Cross on the bass. Any sugestions?

One additional question. Is there any degradation in sound from using bi-wire cables as if they were not bi-wire cables, i.e., as a single run? Thanks Audiogoners.
My speakers require (recommended) quad wiring. I was told to use the same cable throughout unless I had access to lots of different cables to mix and match. Reviewers have that ability, but few of us do.