600 rpm slip limit

[killerbee]

With a bit of trial and error logging, it seems that lockup will not proceed when outside the slip limit of 600 rpm noted in D5072. I suspect this is what has inspired many of the "WOT lockup problem" threads through the years from the performance oriented crowd. At high throttle settings, slip rpm is greater than 600 rpm with stock converters until a very high engine rpm. Oddly, I only recently noticed this, since I don't spend my life killing parts at the track.

For the reverse engineering gurus: is there a way to build a tune/OS with an expanded D5072, say to 1200 rpm?
If not, how can we get inside the 600 rpm lockup?

Thanks.