Sharing files with retoucher via cloud

I want to share a gallery of images in LR with a retoucher. They can seem to make adjustents but can't export as high res tif, is this correct or am I missing something? Without high res exports it's seem like a waste of time to bother sharing via adobe cloud. I know I can share files using dropbox or other methods, I'm just interested in what my options are without needing to export and import files in LR on my end. 

Thanks