Well, I tested this stuff in my Sandbox Test Zoo and it does not work really well for me
For example, I've placed a circular path at some distance to a habitat. On the other side, I have created a viewing area as a dead-end directly within the habitat. The guests would be much closer to the animal on that viewing area with glass barriers - I mean, as a guest, you would be inside the enclosure, so to speak. But no,if there were 5 people in the viewing area, but about 50 guests who stayed on the normal path and complained about poor visibility.
And as
@Aiste mentioned:
This problem can be seen in a lot of YouTube videos from other zoos as well.
So it's not just: the closest point of view = the best