I got a better thermocouple today, so I tried the timing test again.
This time, 20-150°C took 2:22. 150-225 took 2:34, then back down to 150 took 1:50. Cooling down from 150 took longer than I cared to time, but that doesn't really matter so much.
So that means rising up to Soak is at just under 1 degree per second. Rising up from Soak to Reflow happens at just under half a degree per second. Falling from Soak happens at just under 3/4 of a degree per second.