Okay so I solve it, had to use a “list” connected to the uploader which height I set to 1 (hidden:false do not work) then using the callback i a list template to get percentage of upload. Not beautiful code but it works.
An “onUploadProgress” event would be nice for future updates.
My apologies for the delay.
I just can recommend you to use onFileUpload() method which fires in the moment file uploading ends or onFileUploadError() which fires in case of a server-side error during uploading