I don't know of a way to delay the redirect. How about redirecting to a page that pings for status and when the update happens then send to your final page?
Also, Have you checked out Lambdas? Not sure what your exact workflow is, but they may help. If that doesn't work, you may want to check out something likeevents & webhooks. There should be some combination there that will get you what you need. If not, let us know and why they will not work for you.