sCary has posted a reply on The Shugashack from id's John Carmack confirming there is still an ability to mess with the Q3Test timescale and get a speed-up, though it sounds like it's only on a minor scale:

I looked into it some more, and there is still a problem, but it is a different one... The server clamps the speed, so timescale 4 isn't any different than timescale 2, but it looks like there is still about a 30% slack that can be pushed. I don't understand yet how this is happeneing, but I will look into it.

The game play is so messed up with timescale running now that I don't think it is an effective cheat, but I will still try and fix it.
John Carmack