Now.
You find you template.
Create an Device, then import SMNP Template.
When you change the template, it is not imported automatically.
You have to Delete all SNMP OID's (otherwhise dubble import)
Import the script again,

This is an hassle if you want to make the change for all devices that use that SNMP Template.

Better:
Just make it work like with an Threshold Profile.