auto-compression issue

My website is a directory so my members have their own admin panels, where they can upload images. I have been finding that tinypng auto-compression really makes it so difficult for my clients to upload images they give up. I also get http errors; I would still like to use it but I think I would have to use it manually and I can’t see a way to deactivate autocompression. Is there a way to set it to manual compression? alternatively if I deactivate the plugin will the compressed images stay compressed and then I can reactivate the plugin periodically and do a bulk compression. Any advice appreciated ? Thanks