You MUST leave the Spark retard tables under Torque Management>Spark retard vs. torque reduction and Spark retard vs. torque loss at STOCK if you want the trans to pull timing on the shift. IF you hold your cursor on the tables the description at the bottom tells you this. Here is a file that shows which tables can be maxed out and which ones need to be stock.
Attachment 136228 This one is running 7-8 boost on a 5.3/4l60e combo. Many people have destroyed the 4l60e by zeroing the spark retard tables not realizing it automatically disables the transmission side, even if the trans tables are untouched.
edit: I added a corvette servo, Sonnax .490 boost valve (line boosting kit), and Sonnax pinless accumulator pistons to my 4l60E. I installed the parts at 200k. It has survived 12,000 miles under boost, and has 260k total miles. I do service the transmission religiously. Drain and fills every 10k and filter change every 30k miles. I know a 4l80e is in my future since it already has a cam, ethanol, and boost.