When a blog post is displayed to the user, the date that the post was created is shown. This doesn't make sense when you use the start date. We often add blog posts ahead of time, then schedule them to appear later.
Now, we can "fix" this by writing some code in the view. Unfortunately the start date isn't included in the blog model, so you have to get the actual blog post from the database. This is a hack.
This would be easily fixed with a bit of code. You could even add a switch to control whether this is performed:
if( switch says to do it )
date = post.StartDate ?? post.CreatedOn
else
date = post.CreatedOn