Pitou will likely have just as huge nen reserves, meaning she will be no worse for wear despite having acted as a radar station continuously and controlled the puppets. These guys are superior to humans in most ways. I'd expect their life span to be significantly short, though. They matured very fast and have highly damage resilient bodies, which would suggest they will crumble on their own soon enough or cancer will kill them. Maybe 10 years max. No wonder the king took over a country and set his plans in motion so promptly.