Custom Parameter InterpolationWeightY

I’m a fan of the options the custom parameter InterpolationWeightY enables.
But weather the value 50 nor the value 100 does an effect on my instance (InterpolationWeightX = 74). It’s not appearing in preview-mode and not after exporting the instance as well.

Do you have any suggestions?

my code in a 2-master-file is:
interpolationWeightY = 50;

Try it with a capital “i”. There seems to by a mismatch between the documentation and the implementation.

thank you!