Changes. A nonconforming use may be changed to another similar or more restrictive nonconforming use with the approval of the ZBA. When changed to a more restrictive nonconforming use, such use shall not subsequently be changed back to a less restrictive nonconforming use. No nonconforming use, if changed to a conforming use, shall be changed back to a nonconforming use. The ZBA shall determine whether such proposed nonconforming use is similar or more restrictive, and may impose such reasonable conditions and restrictions as are directly related to and incidental to the proposed use of the property. Such conditions shall be consistent with the spirit and intent of this chapter and shall be imposed for the purpose of minimizing any adverse impact such approval may have on the neighborhood or community.