Bi-Wiring is supposed to reduce EMF bouncing around between the speakers and the amp
From what I remember about my old Royd Apex speakers (Transmission line, BTW), they had an option to split the cross-over into High-pass and Low-pass halves, with separate cables to each half. This has the advantage of giving each driver/crossover pairing it's own path from the amp output terminals. As a bonus, I'd imagine that the small but finite resistance of the cables would somehow "decouple" the 2 halves.
I never tried it, as I didn't have enough cable for 4 runs at the time
Cheers,
Ron.