Can we setup Dashboard Gateway servers in a 1+1 architecture? This is so that we can provide uninterrupted external user access to the all new dashboard app in case one gateway server fails.
Dashboard Gateway configuration is manual configuration indeed and so is the load balancing/redundancy of it. There is nothing built-in into DataMiner at the moment to manage this configuration, but you can use any load balancing/redundancy solution for web servers in general.
I know someone who has done this in the past by flipping a DNS entry or changing the IP on the servers when they wanted to switch over from one dashboard gateway to the other gateway. This was a manual action though.