ACDelco E38 VariableSpeedPump

Hello All,

Can anyone explain the calibration on an ACDelco E38 ECU in regards to the 'KefMPC_b_VariableSpeedPump' parameter
First time messing with an ECU. This is on an 2010 Chevrolet Suburban 5.3L, that the previous owner done an AFM delete on the motor. The delete kit bundle he got came with a Diablosport Predator2 to do the AFM delete in the ECU.
Since doing the delete the truck never has idled smoothly. I bought it this way.

Long story short after doing some research come to find out the Predator2 has no option to also delete the VVT settings in the calibration,,,which of course this truck did have but the replacement non dod cam does not have the VVT on it.
I think this may be playing into the rough idle as well...not sure.. a rookie here. The Predator2 would be fine for under a 2010 vehicle i am guessing but for this particular truck,,,nada. Not sure why they/bundle sell it like this.

The value for the VariableSpeedPump is set to 0 which i assume is a default setting but not sure.
Compression,coils,injectors are all good on the truck. It actuallt sounds good on cold startup and after spooling down off of fast idle in about 30 seconds time it starts idling very sparatic. Don't have a high end OBD2 scanner to look at things.
Anyone know anything about the VariableSpeedPump setting,,why you would even want to change that?

TIA