When using pickMultiple or pickAndStore in multiple mode, is there a way to get the returned list of uploaded files in the order they were uploaded?

Filestack has no built in sort function but it is still possible to sort the Array of objects you receive using javascript.

So for example, you could sort the objects by filename.

Here is an example Filestack array:
var blobArray = [
  {
    "url":"https://cdn.filestackcontent.com/tycOAXjbQU2DJR4WGhGl",
    "filename":"facebook_photo.jpg",
    "mimetype":"image/jpeg",
    "isWriteable":true
  },
  {
    "url":"https://cdn.filestackcontent.com/jOBXIKBQtukNEBJFDRjg",
    "filename":"2.jpg",
    "mimetype":"image/jpeg",
    "isWriteable":true},
  {
    "url":"https://cdn.filestackcontent.com/sjoVCCVTT3euKVpzBL5p",
    "filename":"xxx.jpg",
    "mimetype":"image/jpeg",
    "isWriteable":true
  },
  {
    "url":"https://cdn.filestackcontent.com/qATXanFXRjSkcG0onEee",
    "filename":"xx.jpg
    .jpg","mimetype":"image/jpeg","isWriteable":  true
  },
  {
    "url":"https://cdn.filestackcontent.com/KyAh8HNSoWZZOQeAs2mR",
    "filename":"3.jpg",
    "mimetype":"image/jpeg",
    "isWriteable":true
  },
  {
    "url":"https://cdn.filestackcontent.com/x3DpwRauDiAMEeZwj2wT",
    "filename":"4.png
    .jpg","mimetype":"image/jpeg",
    "isWriteable": true
  }
];
Sort by filename code:
blobArray.sort(function(a, b){
 var filenameA = a.filename.toLowerCase(),
   filenameB = b.filename.toLowerCase();

 if (filenameA < filenameB) //sort string ascending
   return -1
 if (filenameA > filenameB)
   return 1
 return 0 //default return value (no sorting)
});