What's the usecase on top of the currently supported comma-delimited list?

Edit: this was confusingly terse, sorry. Expanding a bit.
In Zabbix, further parameter occurrences override the earlier definitions. Changing that for a single parameter to merge the definitions would be inconsistent and might be confusing.
If there is not a strong usecase to prefer it that way, implementing the method, already supported elsewhere (comma-delimited lists), would be preferred.

This could also be considered a duplicate of ZBXNEXT-2943.

This feature (Agent with multiple Hostname) could be useful for such cases:

• Corosync/Veritas Cluster -> Monitoring a Cluster Resource that could be active in a node of the cluster and for HA on another node. The common big problem is coming for Log Items (Active) that need a specific "Hostname". At the moment the only way to monitoring this kind of scenario is to use multiple Agents or Zabbix Sender.

In some other Monitoring tool there is a concept of "Virtual Node/Host", a sort of "host" that could live inside a physical agent for the time that specific "Resource" is living on it. I think is not easy to find a way to solve this kind of scenario but i put my 2 cents only as a reference.

These cases (Clustering) is no longer so "common" but some Enterprise companies could still use this "ancient" technology

Thanks so much