shape of WOT timing advance curve
 

Many of the tunes ive seen have a very distinct look to the WOT advance curve. I made an example of what this typically looks like, please see the image below:
http://www.putfile.com/pic.php?img=4785588

Basically, they get max timing going very early, around 2800-3000 rpm, then have a slight dip around peak torque and then come back up again to finish out. I've found about 10 different LT1 and LS1 advance curves that all have similar shapes.

Is this common practice? If you were on a dyno and tuned advance for max torque at different rpms, would you naturally end up with this same sort of curve?