With Emacs org-babel I just do the refactor using the normal tools for whatever language on the tangled files and then detangle it back to the literate document. There's no problem here.
By "editing" I didn't mean editing the source. I meant the writing process, editing [0]. The thing you may hire an Editor to do. It is not something that you can automate, and the difficulty has very little to do with the tooling.
A slight change in code structure, may require many hundreds of adaptions to the literate document, for example.
It's simply more work - but that "more work" is vitally important, tedious, and resistant to any kind of automated help.