Port forwarding based on FQDN and URI match

Create two pools, one for each set of instances listening on the respective application port (55543 and 55544).

Create a simple iRule that switches between them based on URI:

when HTTP_REQUEST {
    switch -glob [string tolower [HTTP::uri]] {
        "/new*" {
            pool pool_55544
        }
        default {
            pool pool_55543
        }
    }
}

Enable OneConnect on the VIP if you expect users to be flipping between the pools mid-session.