Yes, it is a big loss that Keely's book being burned.
But I still failed to see why Schauberger have to credit Keely? In what way Schauberger use Keely work? I am aware that Viktor Schauberger use a device that force the fluid to spiral on a spiral on a spiral on a spiral. If he have to give credit, I think it should be the scientist behind "occult chemistry".
About vortex, I only see it being active in improving water quality. I don't see it being used in free energy device. Can you mention some device that utilize vortex?
An FE device utilizing Schauberger vortex should not generate heat, it should absorb heat. I think tesla turbine work the opposite of what Viktor Schauberger mention. It should be interesting to see more progress in this area. Water in my cup became fresh cold after few hours of being placed inside HV part of radiant oscillator one wire coil. But this is the furthest I can go for Schauberger methode in electronics experiment. 555 based coil collpase current:
YouTube - Moving neon bulb light #2