Note that voting for much higher rates doesn’t make the rates increase faster. The reason is we use median and not average. So voting for your target rate is enough to make the rates grow at its maximum speed.
Also note that there’s a maximum increase of 1% per day on each duration. For example on 3 months the current rate is 4.5% but the current result of the vote is actually 8%. So if if everybody keeps his vote as is, the rate will be at least 8% in 4 days.