You should be able to set up a Mechanic to do this. Create a Mechanic, and assign it to your source. This way it runs for each character with that Source. Add an Eval script to it to do the work you need.
Then in the eval script cycle through the Powers with a foreach. You just need to go through and find the powers you want to alter this on, and delete the SPCPwrMod tag associated with the Mod you want to remove from that Power. The generic tags get assigned at Initialize/500 so you need to do this after that timing-wise. Here's one that will remove the first level of Device from the Armor Power...
Code:
foreach pick in hero where "component.Power"
if (eachpick.tagis[SPCPowers.s2cArmor] <> 0) then
perform eachpick.delete[SPCPwrMod.s2mDevice1]
~ you can do more of these deletes to remove other Modifiers
endif
~ you can add more if statements to check for other Powers. Only do the foreach once, they are expensive
nexteach