It might possibly depend on the thickness reed material, one big petal seems stiffer to open than smaller ones.
Boyeson dual-stage have one big petal and small ones inside it.
On my 250, 400 & 500's I cut out the support ribs of the cage and run full-size carbon reed petals of .45mm for the 250's and .50mm for the 400/500.
I feel it improves the power all through the range on the bikes that I have done.