If I was a priest I would deny communion only to those who do not believe in BOD (explicit) and BOB (explicit) also. If someone believed in EENS and thought that someone was "putting" exceptions to the salvation rule through BOD and BOB and in addition would consider someone as alien to the faith for believing in BOD/BOB then it would be justified to deny communion.
They would be schismatic because they refuse to be in communion with fellow members of the Mystical Body of Christ. Again the important thing would be first not to deny communion at first, and ask questions later. Once you see someone has pertinacity etc... Or have a clear schismatic spirit then I would have to agree. For the most part denying communion should be something done to public sinners and done very sparingly.