Choosing the operative ice tree in Construction stack

[Bullit]

What is the best way, if possible, that a setting (in this case self.scale) in Post simulation only works in a certain period, while in another period it is self.scale in another tree in Modeling Region?

[Chris_TC]

In the post simulation tree you test whether the current frame is part of the desired time period. If false, you get self.scale and set it without doing anything. If true, you get self.scale, do your adjustments and set it.

[Bullit]

But setting it doesn't mean it is doing something already?