I am trying to tune my 383 using LT1 edit. So far I have succeeded in changing the WOT table for the 0-1200 RPM range. I have also modified the PE vrs RPM table leaning out that particular RPM range. I have tried three different values (-10, -15 -25%). I also locked the BLM's at 0 for WOT.
Results:

The LT fuel trims remain at 0 during idle.
The ST fuel trims keep adding fuel to bank 2. I have a split BLM condition due to the cam (GM 847).

Is there a limit as how negative you can go in the PE vrs RPM table?

Should I start modifying the MAF table to lean it out further?

Any help greatly appreciated.