Having thought about it you're probably right. That properly belongs on a different kind of wrapper around this data structure or ones like it. Maybe in that

Having thought about it you're probably right. That properly belongs on a different kind of wrapper around this data structure or ones like it. Maybe in that /specific/ and /rare/ use case it even makes sense to store the underlying data in a wide data structure; but my supposition is that handling it as a series of fragments (which would have a length in memory and in code-points sizes) would be the answer. If addressing in such a way replacement and other editing operations seem likely.