I guess I don't see any advantage in bi-amping for lows vs highs. Many full range cabs are fully capable of doing this for you without the danger of making a smokebomb out of your HF driver either with low frequency signal or excessive HF voltage. However if you are splitting your pickups and want to amp each to a different amp then you could use a full range cab for each and have a true stereo sound with full control-ability for each side. Sounds like fun with potential for amazing sound with unlimited tweaking possibility.
