I've got the same issue with my 2012 Yukon 6.2 E38. Only fix I've found so far is to just adjust the override parameters from 240 or whatever it was...
I'd suspect the stumble is related to an ignition misfire as indicated by a massive lean spike shown on the log as the large shift in Short term fuel...
I dont think cranking fuel has much input from MAF/Dyn, being that MAF reading is extremely inaccurate at cranking speeds.. InjPW is going down based...