Nice ! We should try to put something in place so that I still get some decent testing for web (testsuite + TCK), otherwise it may become broken in short order.Just make sure that your configuration does not define both.Only difference in configuration for using undertow or jbossweb currently is just what subsystem is configured, web or undertow.I have just send PR https://github.com/jbossas/jboss-as/pull/4329
that adds standalone-jbossweb.xml that has web subsystem instead of undertow.
this way you will be able to run standalone.sh/bat -c standalone-jbossweb.xml
Assuming that you have some customized standalone.xml for running TCK you can still use it the way you did.