I'm not sure what kind of operation you use for array copy +Array command, but it's kind of slow.

I recommend that you change it so that it just sums the array with an empty array, i.e.:

Array + []

Which can be significantly faster when copying large arrays, while maintaining the same speed for small arrays (see below).

For arrays with fewer than 11 elements, the +Array command is slightly faster (less than 0.00005 ms); at 11 elements, they both perform the same, and the difference keeps growing with the number of elements. For nested arrays, total number of elements (i.e. variable size) is the defining parameter.