Good afternoon. Thank you for your kind replies. Before posting I had already tried restarting the system, and also had uninstalled and re-installed the aws-cli; neither of which solved the issue. The only solution I have managed to make work is the suggestion from bdw429s to call /usr/local/bin/aws directly from the name="" argument in the tag.
In the future, I would love to re-map the aws command to the real life, existing version, but I’m not sure how to do that. I have no clue how to do this. Perhaps someday I will find out! It appears, based on using whoami from <cfexecute> that programs are executing under the tomcat8 user.