Up to OAS 6, Wersi OAS instruments only had 144 notes of polyphony, and you could layer up to 5 on the right hand (4 normal + 1 on the auto chord feature) 3 for the left hand and 2 on the pedals, 6 ACC tracks (Excludes the 2 drum tracks which use a separate module) as well as up to 16 on the Midi sequencer, and nobody ever had any problems.
NOTE: VST instruments had their own variable polyphony levels, which was determined by the CPU/Ram fitted.

Bill