Please validate iRule to Load balance the traffic based on SNAT.

Assuming that 1.1.1.1 is routable back to the site, looks fine. Just one tweak that will save 8% compute cycles on the IP comparison

when CLIENT_ACCEPTED {
  if  [IP::addr [IP::remote_addr] equals 1.1.1.0/24] } {
    snat 1.1.1.1
    pool Test_pool
  } else {
      pool Normal
  }
}

I wrote up an article a while back on IP Comparison performance if interested.