For the "temporarily projects those targets as if they’re isolated files" part, you want something like narrow-indirect or edit-indirect. https://www.emacswiki

For the "temporarily projects those targets as if they’re isolated files" part, you want something like narrow-indirect or edit-indirect. https://www.emacswiki.org/emacs/NarrowIndirect https://www.emacswiki.org/emacs/NarrowIndirect https://github.com/Fanael/edit-indirect https://github.com/Fanael/edit-indirect