It depends on the teacher. If the teacher is teaching a limited practice, then it may be a limited practice. If a teacher is teaching a balanced practice, with a broad amount of methods to help you in each situation in your life, and is teaching correct methods, then it may not be limiting to your practice. So it really depends on what the teacher is teaching. Sometimes by staying with one teacher who has a limited practice, we get a limited idea of the practice and then frustration can arise when we are not in perfect conditions for practice. So it would be encouraging for that person, if they find they are getting doubt and disillusionment, to seek other teachers.
We ourselves went to many teachers, we didn't limit ourselves. Other people find they like to stay with one teacher, it depends on the personality. I was once with a teacher who said that the "best" teacher may not be the "right" teacher for you. This teacher explained how it depends on whether your Paramis match, that each teacher has a different emphasis in the practice, and because of our own Kamma, we have different qualities. We may gravitate to one teacher because they have similar qualities to those that we are trying to develop.
Steve and I tend to focus more on Compassion and Wisdom, so people who gravitate to those qualities may like to be with us, whereas someone who perhaps has a lot of Renunciation Parami may prefer to be with a monk. So, it really depends on your Kamma, whether you are compatible with the teacher, and whether the teacher is teaching correct methods for you, because each of us is different. Each of us has different tendencies. Even the assistants here, they will often ask the same question to both of us to get different flavors of answers. So, we are used to having one question directed to both of us, so that they can get a different answer due to our different personalities. And that is helpful for some people, because sometimes if you are perhaps too close to one particular teacher's qualities, the other may be able to see where you are going wrong and balance you. Or you may be able to identify more with the person who has more of your qualities, depending on the situation. So whether you limit your practice depends on the teacher.
And also we try to remember the Kalama Sutta when we go to visit any teacher, and ask them questions. Because in the scriptures, the Buddha is recorded to have said that it is by conversation that one's Wisdom is understood. So you have to converse with the teacher to understand whether they have something to give you or not, and not just judge by the outside.