I was playing a game today with Absolute Zero and Legacy. Legacy was giving his +1 to damage with Inspiring Presence. Absolute Zero had Null-Point Calibration Unit, Isothermic Transducer, Focused Apertures, and Thermal Shockwave in play. So, when Absolute Zero uses the Thermal Shockwave Power does the +1 from Legacy keep Cumulating?
For example, I targeted 3 villain targets and did 3 cold damage to each (1 from the power, +1 from Legacy, and +1 from Focused Apertures) and then I did 10 fire damage to myself because I did 9 damage total to the targets and then Legacy's +1 added 1 more again. Then after that Isothermic Transducer kicks in and I do 12 Cold damage (+1 from Legacy and +1 from Focused Apertures) to my final target.
Your math does indeed look correct to me. Every time Zero dishes out an instance of damage, he gets +1 from Galvanize, and another +1 from Apertures if the damage type is Cold. Galvanize + Transducer is always fun, though Galvanize + Shockwave is not necessarily so.
One thing to keep in mind with AZ...if the fire damage from Thermal Shockwave kills him, he gets no option to use Transducer. But as long as he survives, here's a tip: if you have his other Module in play as well, the Transducer's outgoing cold damage may target AZ to heal him. Without any +1s to your damage, this basically makes AZ immune to any nonlethal amount of fire damage; with a +1, using Thermodynamics to deal 2 fire to yourself and then heal for 3 (or 4 if you have Apertures) with the Transduced cold damage is a very effective strategy. Cryo Chamber makes it even better, as long as you have that +1, since you then can deal a net of 1 fire damage to yourself and get back as much as 4 HP in return (you still need Apertures to hit 4, since your cold damage is up to +3 but your original fire damage was one less than without the Cryo Chamber).
AZ and Legacy really like to hang around together!