its been a few days so doubt you'll read this but, even if you have really advanced fusion tech what people often overlook is that ultimately the civilizations

its been a few days so doubt you'll read this but, even if you have really advanced fusion tech what people often overlook is that ultimately the civilizations are just heat engines. They would still have a heat signature & as you described that would be orders of magnitude more that their respective stars. you could literally track the growth of a type-II civilization by the radiation signature as long as they are emitting anything above CMB. Also, yes you dont have to look for Dyson spheres but you'll agree that Sun has 99.9% of the mass of solar system so it would make sense to turn to it after you have 'used up' Jupiter. And yes you can extract mass out of a Star with currently know physics, its just big project. THAT should be visible from far away. ultimately I doubt there is any stealth for cloaking a type-II civ so whats the best bet? you go the other way & expand as fast as possible. But either way we would have noticed .. at least close to our galactic cluster.