In a solution with 2 IdentiFi controllers in a HA pair, upon creating a routed topology, 2 subnets are needed per routed topology correct? One for controller 1 (local subnet, if configuration is performed here) and the other one (remote subnet) for controller 2.
This leads me to another question: in an enterprise campus, where the APs are spread over several floors but on the same site of the controllers pair (local Data Center in the building), what are the advisable topologies for corporate users (typically 802.1x auth.) and guests (Guest portal)? Bridge@AP? Routed mode? The need to have 2 subnets per routed topology with a HA pair seems to add extra complexity, I would say... Not in the controllers themselves, but on the network infrastructure (if not running OSPF, more static routes pointing out to the controllers to reach those subnets...).
On the other hand, Bridge@AP, with controllers and APs on the same site, don't know if makes much sense also... Is Bridge@EWC the answer? :)