Cannot turn measures invisible in parts
When you turn a measure invisible in the main score you expect the measure to be invisible in the parts as well. It is not. You also cannot turn the measure invisible in the parts.
My first expectation is that the visible flag would be passed to the part, barring this I would expect to be able to change it in the part. Actually you should be able to change it in the part in either case.
This applies to 2.0.3 and 2.1