The only concerns about keeping a ball around your neck don't involve strangulation except for younger children when it would just be trying to hold on.

Most bites that are on the face are cases from the snake being around the owners neck. It's hard for the snakes to hold on and they may feel like they are falling or slipping at some point. You also can't control and see them as easily so a bite is more possible.

They're not climbing snakes, but really theres nothing wrong with it if you're careful. :]