Perhaps each time you stress a component, you add a die to that components pool then roll the pool. Over a certain total value breaks or exhausts the component. This could also be an action roll, where the number of X+ results on dies count towards success? Sort of a risk VS reward decision. I can have extra effect, but risk overheating my mech's systems?
You can run your motivators at 2 dice to avoid a barrage, and have a low chance of rolling 12+ and overheating. 1 success you do it and everything's fine. You avoid the attack. For every success above 1, your heat builds up, and you add an extra die to your motivators pool for the next roll. As heat builds up, you run at a higher effectiveness but flirt with rolling a total of 12+ (or whatever your motivators overheat value is) and suffering a system overload unless you can dissipate the heat.