There is no such option in your documentations :
And it could be handy (snap to, store location etc… ).
What i do now is : make a boll editable, making a branch with Tick input and once the bool is true it passes the branch and turn it into false and then it keeps on going to the next scheduled nodes .
So when i click it on the details panel, it blink and keeps the “false” state. So in generally, it activates as a button, but looks wierd :S