It is only relevant if the file is quite large.
You need to modify HttpJob.PostMultipart.
1. Add a global CountingInputStream variable to HttpJob.
2. Remove the call to PostBytes and instead send the request with this code:
Dim in As InputStream
Dim data() As Byte = stream.ToBytesArray
in.InitializeFromBytesArray(data, 0, data.Length)
cin.Initialize(in)
req.InitializePost(Link, cin, data.Length)
You can now track the progress with a timer by checking Job.cin.Count.