I flagged https://serverfault.com/q/514541/152253 with a custom message:
This question has been asked on SO as well: https://stackoverflow.com/q/17032121/1544337 and seems to get more response there.
As far as I know, you shouldn't cross-post. I found the question here on SF less valuable and best removed, since the question on SO got more response and a bounty from the OP.
However, the flag was declined:
flags should only be used to make moderators aware of content that requires their intervention
Doesn't a cross-post require moderator attention?
What are the guidelines for cross-posts?