When an editor (VE) is sure a whole top level section hasn't been touched, we could send back
<p id="mwAB" data-parsoid-unchanged></p>
with all the content stripped.
For a typical edit on a long article, this would cut out most of the data we have to send back (for which we can't use HTTP compression and have to try to do it the client (T68914), which can be slow too).
Local tests on a copy of [[Barack Obama]]:
| Document | Full | One paragraph | %age |
| convert | 215ms | 22ms | -90% |
| deflate | 303ms | 26ms | -91% |
| upload | 9000ms | 888ms | -90% |
| total | 9518ms | 936ms | -90% |