In our environment we have a lot of hosts that require setting custom thresholds (i.e. user macros / user macros with context). The environment is very dynamic though. New hosts are coming online all the time and are automatically added to our Zabbix instance via some custom code. What would be nice is the ability to specify a user macro at the host group level so that any host that is added in the future to that host group will inherit the user macro override from the host group level and not just from the templates it is linked to.
For example: If I have a host group of "Site A" with hosts "server1" and "server2", I would like the ability to set user macros against "Site A" so that if a new server comes online "server3" that it will automatically inherit the user macro. We've encountered many cases where a new server comes online and it inherits from a Template which has suitable macro values for most of the hosts, but not all the time. As a result false alarms for certain triggers fire causing unnecessary emails to be sent and then we have to go and set the user macros on the new host. Adding an additional layer to the macro hierarchy (global -> template -> -> host) will definitely improve the monitoring experience and help with administering Zabbix in our dynamic environment.