Currently SNMP version and SNMP community string (login and password in case of SNMP v3) are set on per-item basis. But this does not correlate with real life, where different hosts may have different SNMP versions and credentials, but where it is impossible for one host to have different community strings for different SNMP OIDs.

In this case if we have several devices of same model but with with different SNMP community strings set, the only way to make everything work is to clone the template, change community string values in all items in this template, and then use one template for one device and another for another device.