Big minus for increasing the timer.
Big plus for decreasing the timer.
Both opponents are in максимально equal conditions.
So, you are again in favor of equalizing the chances over the distance, regardless of skill? This, to put it mildly, contradicts the idea of a mirror match. Anton said it very accurately - there is always something to do and many complex battles from the start. A newbie won't be able to handle these complex things, no matter what the timer is, so a short timer is almost always beneficial for a weaker player. The exceptions are a few players I've seen, like Jurist and Dark, for example, who both play well and click as fast as Starcraft players.
