We have an existing case (47931) about the issue where disabling WHM > Packages > Feature Manager for a feature list by unchecking "Ability to Trace an email address" does not remove the cPanel icon for Email Delivery Route under the Mail area. In order to get this working where it is properly detected, simply add the following line to your existing feature list:
Please replace featurelistname with the name of your feature list, so if it were dnsonly it would be /var/cpanel/features/dnsonly. I tested this on my own machine and I was able to get that icon removed by adding that line to my feature list. I've attached a screen print showing the interface with the option removed.
echo "deliveryreport=0" >> /var/cpanel/features/featurelistname