It is interesting to see how the bumf for a given technology/engine/antitorque system has such endurance, and so little in the way of hard engineering.
The wankle died when the first oil crisis made fuel economy top priority, and I know of no major improvements that have raised it into the piston engine pack. Fuel economy is critical for pistons, since they exist only because the extra weight they have is offset by the lesser fuel they burn because range is the operating parameter. I have heard 9and can't find right now) that wankles eat about 10% more fuel per HP than a piston.
BTW, I saw that previous post where the erstwhile engineer had a rotating piston engine (a variable ratio displacement rotary engine, I think) where he could get a zillion HP out of a 125 lb engine. Yes, and also it runs on cornstalks and sea water.... If only engineering were so simple!