Maintenance Page redirect

You can definitely serve the maintenance content from a VS on the BIG-IP, and the content can contain a timing element that will cause the client browser to refresh the page. See this link for an iRule example: https://devcentral.f5.com/wiki/iRules.LTMMaintenancePageLite.ashx

You would need some way to distinguish between the first time a client attaches to the virtual server and any subsequent connection, but an HTTP cookie would probably accomplish this.