Thanks that’s very useful. The scheme we had in mind was very similar. To avoid the parsing we thought that when we generate the MAGIC_NUMBER, we could update the index.html and generate a file version-MAGIC_NUMBER.text. Then the front-end just needs to make a static-file request for that file and if it gets a 404 then it knows it should prompt the user to update/refresh. This means that if you make small changes you don’t need to delete the previous magic-number files, when you do want an update to prompt the user you just delete all the previous magic-number files.
I guess the specifics aren’t really all that important, I just didn’t want to go down this path and do all the implementation only to find that there is a standard way of doing this. Thanks again.