After all that why didn't you pull some of the bearing caps as suggested? If you pull a rod cap there should be a numbers stamped on the same side to match them back up again. The main bearings are numbered and have an arrow towards the front so you don't put them on backwards.
At this point do we know the
oil pump failed causing the lifters to bleed down and fail and bearings to get destroyed. But we are not really sure on the bearings yet because none of the caps have been pulled. If that one rod got that hot usually it is obvious if you wiggle it back and forth. And why just that one. Pull that cap and let's see.