I have a bunch of devices that do not support multiple NICs, hence the IP address would always be the same, regardless of the port / interface type.
For cases like this, is there any quick protocol tweak to have one single "IP address/host" field
in the "Element Config" screen?
I don't believe the current syntax allows you to define multiple interfaces that share some fields. There are polling mechanisms like multithreaded timers, dynamic polling, and raw SNMP polling that allow you to use multiple IP:port combinations within a single element, but this is usually to poll the same parameters from different endpoints.
We usually don't want to enforce certain behaviors like IP address uniformity through multiple interfaces in a connector, because users may have set up their network in a way that does not conform with the usual expectations.