I think you should be able to collab with people on a project like you do on google docs or stuff like that. You should be able to share privately projects to people and make them be able to edits that change the project. That also means yous should add a history and a undo option just in case your partner goes bassare.
If you find this multiple times, that just because I want to share my ideas and most of the time when normal not famous people share these ideas, no one reads them.

forever
say [Deal With It]
end

People do read these ideas, it's just that it can't be implemented because of how hard it would be and the problems there may be.
This post on another topic like this says more about it.

Also, even though this is about collaboration, this actually fits better in suggestions. But it's already rejected, so I don't think there's any point in moving it or making a new one.

I put this in suggestions but I copied this post couple times to get attention.

forever
say [Deal With It]
end

I think it would be a good idea if you could make private studios that the scratch team can still moderate like any other studio. perfect for collabs.