Redirect to pool and remove path

HTTP::path [string map { /* / } [HTTP::path]]

you cannot do that because it will change all the path of maintenance page objects such as image, css, etc.

you may try something like this.

e.g.

[root@ve11a:Active:In Sync] config  tmsh list ltm rule qux
ltm rule qux {
    when HTTP_REQUEST {
  if { [active_members [LB::server pool]] < 1 } {
    switch [HTTP::path] {
      "/f5.gif" {
        pool maint
      }
      default {
        HTTP::uri /
        pool maint
      }
    }
  }
}
}