I wouldn't worry too much about the health of YS guys. YS is the preferred engine of warbird pylon racing. Those guys go through a lot of engines and keep the service center busy. It is not uncommon for the race guys to use 50% nitro either. Last warbird race here in Sacramento had 70 competitors including Tatsuo Yamada himself. The next one later this month is dubbed the Warbird Nationals is a 3 day event and is open to 100 entrants. YS is also a thriving choice for helicopters. IMO there are more YS engines in use today then when they were the preferred choice for pattern, just fewer of the large 4 strokes. IMO YS will always support F3A, that is where their roots are.