Did you eventually find out how to change this? We are seeing that the description input configuration is not responding to changes. We are getting per host description data once a minute even though we have configured the add-on to poll every 3600 seconds.
We have tried different configurations and we have tried restarting Splunk.
Splunk Enterprise 7.3.1
Splunk Add-on for AWS 4.6.0
OS: Amazon Linux 2