The flag/close dialog has several serious issues. The easiest way to see these is to review the responses to Question Close Updates, most of which have been unacknowledged (publicly) by staff.
Issues include:
- The flagging dialog should not put all the custom close reasons under the heading of "needs improvement"
- The "too broad""needs more focus" reason is not only about posts that ask multiple questions. It is also about questions that are too broad and which it is unreasonable to expect to be answered in the SE Q&A format.
- When you've voted to close with a site-specific close reason, you can't see which one you chose at a later time
Please consider implementing Machavity's very clear proposal.