Some newbie questions - automating deconstruction

Heyya all, just started the game and its fun but im struggling with how to link the deconstruct action in the AI behavior

I found a thread about a similar thing from 2 years ago and this is what I ended up with: https://i.imgur.com/7fveRrI.png , but I guess things changed since then because it doesnt work anymore

My dasher successfully paths to the unit marked for destruction but then he doesn't do anything - just placing the target unit into the signal register doesn't actually tell him to set the Target register for the deconstructor too, and I can't find how to fill it in the behavior flowchart either.

As for the main goal I want to make: I want to start replacing runners with dashers, and since I have many I dont want to deconstruct them manually