I think his question is more about the writing part. He wants to be able to convert the modified Dense Cloud data back to the 'oct' file so it can be opened in Photoscan again.
That would be nice, although I think there is some checksum going on as well (I tried altering a Photoscan project the past, and it did not open after re-zipping).
I would also like to be able to import Dense Cloud data, perhaps we should make a feature request for an official 'import points' feature?