It is the Engine of Choice, for Home Kit Airplanes.
I think the propane/butane Wankel Generators, that substitute for small Batteries, Is where Wankels will have the biggest impact.
Portable Power Tools, without Batteries.
Now if whe have Wankels invented 25 years earlier, They would have a tremendous Impart on the development of WW2 Warbirds.
Edit
They Work well in Hybrid cars as well.