Splash File Redirect to original homepage within time frame using ifile html content

You cannot create a second response in an irule after a delay, because HTTP is a request-response protocol (unless you implement AJAX in your splash-page).

You can only do this within your splash page HTML.

e.g. https://answers.squarespace.com/questions/26762/how-can-i-redirect-from-a-splash-page-to-the-home-page-after-a-few-seconds.html