Sounds sort of interesting, except easily implementable with the bad old 'string replacement' as a skill/tool or something? In fact harnesses probably already have some such abstraction?
I believe openode uses a tool that requires line numbers and the model needs to write the entire line again. It also prevents it from making changes if it hasn't read the document since it was last changed.
There's certainly improvements, but no, the simple cli commands arn't properly made to do what a dumb model wants to do, since the dumb model isn't ever going to consider there's a bunch of other Donalds or Trumps or DTs that are completely innucuos