In a well controlled process it should not be common. Bigger parts have been casted before without issue. Tesla cutting corners?
Given what we have seen from Twitter, cutting corners and ignoring laws and regulations seems to be an Elon thing.
The guy is even skipping rent.
So why not?
This shouldn't ever happen if QA is being done properly.
EDIT: which I recognise is "cutting corners" but the point is, any idiot can make one in-spec part. Making them consistently is the challenge.