Changing the autoloading namespace does not allow you to use your own fork. The autoload config is related to the code, not to the VCS repo where it lives. You cannot change it if you don't change the code.

And as I said in my other comment, you don't need to rename the package to be able to use your fix. And even in the case where you want to rename it, you should do it in a separate branch, not in the branch being used to send the PR