Storing mutable arrays in flash

Well, you can't create an array that way that you can write to, but you can make it so you can read from it and store it on flash. This should work:

arrays.push(new Uint8Array(E.toArrayBuffer(require("Storage").read("test"))))

So then all you have to do is write a function that'll handle writing the array. However it's worth noting that when you write the array (unless it was all 0xFF and you're setting individual bytes) it'll need to be re-allocated so will be at a different address, so you'd have to update it with the line above again