ec2 Run Instance Request with Launch Template and a overriding network interfaces specification

I am attempting to automate some instance creation using a Launch Template. As part of the RunInstanceRequest I sometimes need to specify that my instance be on a different network(s). While this works fine if the LT has the same number of devices (or less than), when the LT has more interfaces than what I specify in the RunInstanceRequest, the instance inherits the unspecified device specification from the LT.

So for example if my LT has two devices and my RIR has one, my instance gets two interfaces.

Is there a way for me to override this behavior so I can create my instance with a network interface spec which completely overrides what is defined in the LT?