So, I'm integrating the butler pipeline in my game project, but I already have some builds updated frun the browser that have several hundreds donloads... Now i would like to be able to push to those containers with the butler, so I can deliver the update to whoever donwloaded the game, but it seems to me that this is impossible... or not? :D

It isn't possible at the moment - it's a feature we might add later. That doesn't mean you can't start using butler, though - the first push will just take a while since it'll upload the whole thing!

Of course, and I did :) I was just wondering if there was any way of not having to reset the download counter when starting to use the butler, as builds get added on new channels.