So, it was the last fluid to get done on my landy everything else was done last summer.

after the oil drained off I noticed this sharp metal edge just on the inside of the drain plug casing

anyone ever seen this type of poor casting before?

unsure when this oil was last changed, but there wasn’t much debris at all on the magnetic drain plug when removed

Not so much poor casting but a fail to tidy that flashing off after removal from the mold.
No bits is good news.