No, it won't because parser would have to be reset in `parse_event`, not `parse`. However, new draft states:
```
   Every XMPP stanza or other XML element sent directly over the XMPP
   stream (e.g. <features xmlns="http://etherx.jabber.org/streams"/>)
   MUST be sent in its own message.  As such, every WebSocket text
   message that is received MUST be a complete and parsable XML
   fragment, with all relevant xmlns and xml:lang declarations
   specified.
```
So it will still work with new XMPP over Websocket but perhaps indeed reset should be done in `parse_event` anyway to provide more complete solution.

When deciding to reset after each element, I trusted `timer:tc` result, which benchmarked parser reset at ~7µs.