It really should be possible to modify one form field that was in error without invalidating the whole document.

If George, Becky, John, Jim, Sally, Jesse, Fred and Paul all sign a document in 8 places, and one line item in one place erroneously says George and not Becky, then it should be possible to switch George's field to Becky without all of them needing to re-sign the entire document, which is a giant annoyance and waste of time.

Because, ya know, people make mistakes.