Sorry for being late.
In some environments I manage, I "excluded" some webapps deconfiguring them via Deployment Manager. That's the most clean solution and somehow "most definitive" solution, the app will not appear in your deployment registry any more.
In others, I just modded the installation, renaming the appropriate XML file in
[config]/LevX/Web/WebAppServer/SASServerX_X/conf/Catalina/localhost/
So, at restart, Tomcat won't deploy the app.
Hope it helps.