You can use Pipistrel Vario Prop performance charts from either Virus or Sinus POH; plenty of relevant information in there.
Long story short, you acquire your set engine rpm then coursen the pitch to your set MAP, and then make fine adjustments for desired cruise speed. In general 26 MAP at 4800rpm will be most economical cruise for a 912 up to critical height for that MAP.
When you adjust back to fine pitch you adjust your rpm down first, then pitch fine to MAP, to avoid over speeding the engine... Going to a course pitch its the opposite, pitch course, rpm increase to MAP
Cruise 25-28 MAP
Downwind 23 MAP
Final 18 MAP
With all those flight modes and MAP settings you can set 5000rpm as your target for all of them; the CSU governor will hold 5000rpm