Defines the maximum size beyond which arrays cannot be edited when multiple objects are selected.
This value controls the maximum size of arrays that can be edited during multiple-object-editing in the inspector. When you have GameObjects selected that share arrays larger than this value, the inspector will show an empty array.
Prior to Unity 5.5, this value was hard-coded and could not be changed.
A default value of 64 has been chosen as a good tradeoff between performance and utility. If your serialized object typically has arrays larger than this, you can set this value to a higher number to allow multi-editing on those arrays. Please be aware that setting too high a value might affect inspector performance when editing large arrays or a large number of objects