It will be great if you enhance your HA feature and introduce a real cluster scenario for High Availability (master/slave) deployments.
We have performed a lot of tests and we have found delays and freezes from master to slave transition. Defining LAN as the only interface to declare a failure is not enough. For mission critical setup I believe this is crucial and Peplink should invest on new possibilities. The ideal scenario is for both devices to keep the sessions and the switch over to be tranperent.
Let me know if I can be any help.