At least one solution seems to be to modify the iwp_home.html file to do the redirecting. This disables the default "list of databases" page or otherwise bypasses a custom home page if you've created one, but it serves the purpose.
In my case, I modified iwp_home.html to include only this chunk of code, which immediately redirects the browser upon loading the page. Hat tip to Sydney:
This functionality is needed as part of the design of a particular solution, therefore at the client/ script level and not requiring a server side hack.