The Mixed Transparent method allow you to use the Load-balancer for both Active Directory connections and computers using the transparent method.
Play with your own gateway: Your gateway is able to forward (using DNAT ) HTTP/HTTPS requests to the HaCluster Load-balancer.
Computers that use the Load-balancer address in their browsers settings still use the standard method.
if your gateway cannot perform DNAT, set your HaCluster as the primary gateway. HaCluster will be able to perform the same operations as a standard gateway.