You don't have to wait for your images to finish uploading to Reconstruct in order to create a point cloud. You can choose to process the images while they are being uploaded. This feature means that you can start the upload, indicate that you want to process the images upon completion of the upload, leave your browser open, and walk away from your computer. There is no need to babysit the upload process.
Please note, that you have to leave the browser tab open until the upload process is completed. If you close the browser before the upload is completed, the images will not make it to Reconstruct, and the point cloud will not be created.
You can also process your images to create point clouds after the images are fully uploaded to Reconstruct, by following the instructions here.