[brianwski]

> Why can't I have my cake and eat it?

:-) We definitely plan to add an API to append to an existing file. The current largest file size is 5 GBytes, and we want to support much larger (imagine a 1 TByte encrypted disk image). That will be by appending chunks to files followed by a "commit" declaring the file as complete.

I think the reason most of us cloud providers don't like replacing parts of files is it helps our caching layer be much simpler, and it would change the SHA-1 checksum on the file which just means "more complexity". But it isn't out of the question, it might just come with a "cost" (like you can replace the span but it might take a while and then we provide you the final checksum of the whole file in the response).