Components and null inputs

Hello everyone!

I am working on a script for stadiums for my master thesis. I have scripted 8 different layout curves around the pitch and a possibility to choose which will be the input for the next part based on the number of segments (see “immagine1”).
Afterwards, I want to provide a choice for the stand typology that might be applied (option 1 or option 2) using a gate filter. In this way, I should be able to avoid null items to be inserted as inputs in the next phase of the script (See “immagine2”).
However, that is not the case! Even without an input data, the move component produces a series of null items (see “immagine”). Is there a way to avoid this problem without always cleaning the trees!