Use of the interphone and override functions is certainly realistic, acceptable and in some cases maybe preferable, but it's more a matter of what the practice is at the facility you control at, rather than what you might be told here. In the absence of a local policy or practice, you may find that some controllers dislike being overridden or hailed on the intercom, some are fine with it, still others aren't clear on how to use it. I would suggest you check local policy and/or poll the folks you control with.