One of advertised "New in 3.4" features is the option to use user macros in item update intervals. This is a killer feature if you need to temporarily change update interval for multiple (100+) items. And although it does its job, and intervals change, it also beaks graphs. Basically graphs containing items with macro as update interval will display error "Incorrect value for field "delay": invalid delay". Setting macro value to new style (30s, 1m, 2h) or old style (30, 60, 7200) has no difference.

Funtion request: ZBXNEXT-1675
Function description: https://www.zabbix.com/documentation/3.4/manual/config/items/item#configuration