I also think that this is a little bit over the top. ;)
Okay, I debugged the HTTP traffic using Fiddler2. When my Mozilla Firefox v39.0 requests a thread page it uses a normal "GET", but with a "If-Modified-Since" header.
Request (excerpt)
If-Modified-Since: Fri, 31 Jul 2015 17:14:31 GMT
The AO...