I'd use the Maven plugin, since it is working for you.
Personally I stopped using IDEAs app server integration a long time ago. It was just too much of a pain for me to support it for all the developers on the team. For hot deploy of web resources I usually make a simple ANT target and bind it to key-chords in IDEA for rapid development cycles.
I feel the same, haven't used IDE + server integration for a while.
I got it working from inside IntelliJ.
The error I got was related to @PersistenceContext and hot deployment. I have seen in the jboss jira there is a pending issue about this.
I have changed the BookingAuthenticator class so it uses a SMPC (@Inject in bookingAuthenticator instead of @PersistenceContext, created a producer field for entitymanager)
Apparently this solves my problem when redeploying the seam booking from within IntelliJ Jboss Server integration.
Changing some stuff in AuthenticatorBooking worked with a simple deploy.
When I changed the BookingLog, it did not work without rebuilding the project.
I suppose a rebuild project will cause the implementation class of BookingLog to be generated.
My observation is that a normal build does not recreate the implementation class of BookingLog interface.