Beyond what's already been said, the specific type of damage seen on the lifters seems pretty consistent with what I was advised
might be an excessively high concentration of ZDDP.

According to the lubrication engineer I briefly emailed back and forth with alot of years ago, too much ZDDP can cause spalling and pitting.

Just repeating what I was told, have no idea what's really correct, but he described ZDDP additive use as an attempt to achieve the Goldilocks zone of just-right PPM,
and if you double the amount it usually has the opposite effect of what we want.