Hello Pecck, the space where I am working right now is kind of an oval of 9 ft by 12 ft and I see that the section of 9 ft is too close for many shots.
10 ft would be a little too close I would say since that limits the amount of movement of the subject and the area that can be shot successfully ( the person can not extend the arms completely, shooting 2 people together tends to have some issues sometimes, etc.)
If you dont have another place then you can make it work with 10 ft but if you can choose, I would recommend at least a 12 ft circle.
And thanks for the compliment, I have been playing and testing for quite a while with this and have some information to share, but for sure there are plenty other people MUCH more experienced than me in the forum, for example David Cockey that was the first one that answered your post.
Anyway, let me know if you have any other questions.
Leo