The question: when should I use InvalidateMeasurement and when shouldn’t?
You should only use InvalidateMeasurement when you want to make sure that a following call to “MemoryMeasurement” or “MemoryMeasurementParsed” does not return a Measurement which has been started before your call to InvalidateMeasurement.
Not every call to one of the MemoryMeasurement properties results in a new measurement, instead a measurement which has been taken previously can be returned.
When you send an input to the game via the functions provided for this purpose, this will also Invalidate the measurement. But not only up to the time of the input, this invalidation extends into the future to account for delays in the eve online client UI from input to reaction.