Extract time step filter not not working as expected
Even though you use the Extract Time Steps filter to limit the time steps to load, you still get all those time steps you didn't want.
Here is the problem. The Extract Time Steps filter works by modifying the
TIME_STEPS information given in the request information phase of the pipeline. When you apply this as a filter in ParaView, the source is marked as Ignore Input and new filter reports only those selected time steps. If you then hit play visits each selected time step and everything works as designed.
The problem is that the filter still makes it to easy to get data in unselected time steps. If the filter gets a time value different than what was selected, it will happily send that up to the source and give you data for a time value you didn't select. This can happen a lot. For example, when you first apply the filter ParaView, might not immediately change the time and refresh, so you end up with the same data from an unselected time step. An even more important example: you should be able to create two Extract Time Steps filters to get data from two different time steps simultaneously.
In the update request extent pass, Extract Time Steps should modify the
UPDATE_TIME_VALUE to match one of the selected time steps.