I do this daily, super simple.
First, Snapshot that project, then do not touch the snapshot version, just a good habit to get into.
Next, if you’re not using Frame.io, which I find invaluable (when the client finally gives in an goes along with things), place these revision notes into your project with Markers. “To Do” markers exactly. Then no matter what you edit, those markers are still in the exact place they need to be. Even if they shift in relation to timecode.