Can't remember if i requested this before, but i still think you should be able to Refresh components such as ZExpression, SpawnModel, Repeat etc.
Sometimes you just want to fill a persistent array using a ZExpression, and the most convenient way for that would be to create a ZExpression in ( for instance ) App:Content, select it, and press F5 to run it.
Similarly, sometimes you want to test the results of a condition without creating / waiting for the condition to be true in your project or temporarily overwriting the expression manually.
K