Open discussion for anyone interested in this area… Especially those who’ve worked on similar projects before (how did those go?). Thinking about building a prototype in the future (both commercial / non-commercial applications)… But not sure if its possible to create a worthwhile Sim or WORLD that can run reasonably well on both VR / PC (too much of an ask)… Plus, is it possible to make a worthwhile Sim without needing external solutions from Nvidia or others (fluid / wave) … Just using core built-in Physics / Sim mechanics of UE. 
No. Just no.
The engine can’t even render, and you want it to produce minimally accurate simulation results!? XD
Stick to the 3rd party stuff that works, and For a VR project Unreal is likely the worst possible pick out of a heap of bad choices.