Is it better to reduce fixations?

Fixations don't necessarily need to be reduced. They're often a source of security, focus, and enjoyment, and can even become strengths. The guide is "does it interfere with the child's or others' daily life, safety, or learning?" If it doesn't, it's fine to watch over it; adjust only the interfering parts, searching together for alternatives or compromises. Trying to eliminate all of it increases anxiety and can even intensify it. Aiming for "getting along with it and choosing the setting" rather than "getting rid of it" is more workable.