Thank you so much for using all this time on me. I need to learn to be a lot clearer.
"Return to contact sheet" was supposed to say "return" (ie pressing the key called return) which returns to the contact sheet.
Keyboard maestro does the whole sequence (more actually but that was to illustrate the issue) so I only press Command s.
The last bit: "but we can prevent the upload UI from appearing (you'll see it in the Tasks panel and you can reopen it by double-clicking its entry in the list)" is another version of what I was trying to ask for in my first point on the first possible 5 solutions (the ones you answered). That would be amazing. Just in the task dialog and people can double click. That would perfect as the automatisation software can just wait a second or two and then its on the contact sheet and can continue is usual and there is no difference between when the pop window comes or not.
Thank you and sorry for the lack of clarity.
Ulrik