Had a 2019 DFM 5.3L Silverado come in just out of warranty.....Has had 3 bank 1 lifter sets & 4 bank 2 lifter sets replaced under warranty. #8 misfire with no movement of the intake rocker arm. Severely bent pushrod was found.
Recommended a used K2XX AFM 5.3L engine with a AFM delete using GM Bowtie Lifters/Non-AFM camshaft & a custom tune. Customer declined as it rivaled a new DFM engine install.
DFM will prove FAR more problematic than AFM if it hasn't already. K2XX chassis already had a sporadic history of bending pushrods on AFM cylinders.