Assuming I'm seeing that pic correctly, that the 3rd lobe from the left is worn down, leaving a peak on the left side of the lobe: Frankly that looks like one of three things: Improper cam break-in OR lifters were removed and not replaced in the same position OR old lifters were re-used with a replacement cam. Of course, a defective new lifter or defective new cam could cause it as well. Improper cam break-in can ruin a new cam in 1000 miles but you don't usually see ONE bad lobe. However, putting used lifters back in a different location will grind down a cam quite rapidly. What is shown in the pic is typical of that sort of wear. Lifters have a convex surface when new. When they wear against the cam, the lifter surface can become concave. If that concave lifter stays where it was with the same cam it will work fine with no issues at all because the cam/lifter have worn-in together. But if the concave lifter is placed in a different position, it can quickly grind the lobe away. If a lifter is still convex and put in a different position, it MIGHT be fine; it might not. The "rule" is you ONLY re-use lifters if they are going back with the same cam they were with and in the same location. Frankly, NEVER re-using lifters is a safer rule! If none of those things occurred with that engine, it may be a lack of oil (somehow - not sure how that would occur) to that one lobe/lifter. Since it only appears to affect one lobe, the choice of oil/additives is unlikely to be relevant. The only other thing that occurs to me re that wear is excessive valve spring pressure. But the only way that could occur is if someone put the wrong spring under that valve or if the coil was binding. Though if someone installed heavier springs and the cam wasn't as hard as it should be, that could happen.