A problem was located. Seems the the lower boost pressure sensor wire came in contact with the a/c compressor under load intermittently and wore through the jacketing, grounding it out and causing false readings to throw the P0236 soft codes & intermittenet safe mode operation.
They repaired and rerouted the harness, so we'll see if this holds up.

 

is this lower boost sensor located on the lower ic pipe coming from the ic to the intake manifold?

 

Wiring losing voltage between the connections. Even the tech was wondering why they dodn't say to use solder or why GM just didn't make a complete plug in play kit. I've had no other issues since the solder.