Bummer to hear about the adjusting wheels melting. I don't think it's that you're not using the brakes right. 500 feet is not much of a descent.
If the brakes were really "overheating" they would be fading. The calipers are going to get hot, that's the nature of brakes. I think Avid made a poor material choice for the adjuster wheels. It should be pretty easy for them to switch materials and eliminate the problem. Hopefully they come out with a retrofit.
In other applications I've seen disks glowing red and still functional with no permanent damage.