You can upload multiple shots/batches just not from the same tab. Multiple batches can be uploaded at the same time through different tabs in the same browser. I realize this can seem like a delay in your workflow, however by uploading multiple batches in different browsers, all of your images can upload simultaneously instead of one batch having to finish uploading before the next can start. This will ensure that all images/batches are uploaded at the same time and therefore get returned even faster.