Hello spquinn,
having a look at you 200 rad/s case I notices that the max velocity is at around 90 m/s.
We suggest that for incompressible simulation the velocity should not exceed mach 0.3 (103 m/s).
So this case is already pretty close to that suggestion.
Therefore I would suggest switching to the compressible solver.
Also i would suggest ramping up the rotational velocity even for a steady state simulation.
You can do this via table input to your mrf.
I would suggest ramping up the rpm within the first 500 iterations and simulating the further 1000 till 1500.
Please let me know how this worked for you.
Best regards
Sebastian