Truck runs in the upper 3-4K + rpm life... Injector is about 350% over according to flow sheet.
Don't know what oil pump is in it. Nor the ptw or gap. Thought ptw was built into the piston from MAHLE?
ptw clearance changes as you hone the cyl walls so while mahle may make the pistons a few thousands smaller, that doesnt mean that the machine shop didnt open the cyl up too much and create too much ptw clearance.
the fact you are not getting any blow by out of one side of the engine leads me to believe thats not so much your issue but something is not fully seated or cant get seated. the LBZ engine i just built has 0 blow by even when first started and ran hard but that is on cast pistons and rings for those pistons, yours is a little different setup.
let that engine get up to temp and put some heat into the system, then go playing with it regardless of the heat soak you are worried about. see if things start sealing up then