I think a safe bet is a rate that is slow enough for the slow ramps which would be good for the fast ramps too. Did a quick check of the Dunham info and found some good data for you: (glass type and thickness, fast heat rate, soak time, slow cool rate)
0.5" marble, 107 f/min, 15 min, 18 f/min
1.0" marble, 26 f/min, 15 min, 4 f/min
1.5" marble, 11 f/min, 34 min, 2 f/min
0.5" pendant (laying on it's back on kiln floor) - treat like a 1.0" marble
*Looks like he doesn't do a slow ramp up, but I do it because of my quirky kiln.
Remember, internal stress caused by improper annealing may not show itself for some time or until some mild shock is introduced. I've heard several stories of glass pieces cracking months after being made.
Hope it helps
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