I have a few days left before my exclusive contract expires on another site; does istock have an option to allow uploads but not put approved image for sale; similar to the "opt-out" option as SS. i would like to get images loaded and ready for the opening day.
You can't really upload to IS without the risk of images going live before your exclusivity ends, but to improve your workflow you can use deepmeta and prepare all your files (i.e. keywording, CV mapping, categories) offline.
Than it will take no time to submit them once you're free to do so.