Paul,
           Just setting up the oil filler to find the factory set up is
very complicated, which is easily by passed. That leaves the question of
a breather.  What have others done?? I am tempted to simply put a
breather pipe into the intake somewhere.   Neil.

Well Tracy had to build an air oil separator because he modified the
RX8 center housing.  I think feeding it into the intake manifold is OK.

The rotary does not use a lot of oil if you mix 2 cycle oil with the
fuel.
In fact some survives and make its way to the oil pan increasing the
volume of oil in the pan. Therefore I would change the oil about every
50 hours.

Paul Lamar

Think that over carefully. On my son's rototiller, apparently somehow a
slug of oil went through the breather hose into the carburetor intake,
stopped engine, great cloud of smoke, lots more trouble followed.

Al Rees

That was a piston engine. The rotary has very little blow by.

Paul Lamar