I posted a question on StackOverflow that I think could have also been posted on Programmers.SE. The question has gotten no answers on SO. Is it bad practice to post the same question here after giving it time on SO? Or should I flag my own question as off-topic to recommend it get migrated here? Or should I leave it alone and not cross-post since it wasn't flagged as off-topic by others on SO?
Questions shouldn't be cross-posted - if your question happens to be on-topic on more than one site, ask it based on the kinds of answers you want to get. Your question, however, doesn't appear to be on-topic here. It's best to continue to refine your question (if you can) and leave it on Stack Overflow. It looks like an implementation issue to me, and not a conceptual question.
Do not cross post.
In general if a question is more suitable for Programmers than Stack Overflow then the appropriate action would be to flag it for moderation attention and ask for it to be moved here. However your question is about an implementation issue, which makes it off topic for Programmers.