Question on HTTP Persistence and iRules

You are correct. There'd be no point in trying to use URI-based pool selection if it wasn't able to select different pools on subsequent requests. A common example:

when HTTP_REQUEST {
    switch -glob [string tolower [HTTP::uri]] {
        "/images/*" {
            pool images_pool
        }
        default {
            pool app_pool
        }
    }
}

You may, however, need to enable OneConnect on the VIP to allow the server side connections to bounce between different servers. And if you were using the built-in cookie persistence, you'd actually get two different persistence cookies for the two pools in the example.