Would shooting laser or UV light at an inverter make it permanently slower?
It sounds like you want to use something similar, yet inferior, to laser trimming. Aging is a non-linear process and depends on your substrate and doping. Not only that, but typical accelerated aging processes (by heating) can take days. For instance, the graph below from this paper



That's BaTiO3 with different dopants. 

It's hard to find much information about this, likely because it's not a very great idea.