yep, discovery uses one snmp interface on the host or the other, I cannot setup some network interfaces to use one and other network interfaces to use the other. Even if using two different templates, I cannot get this to work.
You can reassign which snmp interface ont he host is run against an item, but not for LLD items it seems... so I cant discover on one and then reset to the other later manually.
Why does Check Point do this? makes monitoring needlessly difficult. In fairness this doesn't seem like a Zabbix issue since it also exists in Cacti, Nagios, Icinga, etc....