Is there ever going to be an option to have Intermediate as a component state? Building checkboxes would be SO MUCH EASIER if this were the case. Take a look at the checkbox component in angular-material and you will see what I mean.
Currently I have to use dynamic panels and just to have a simple intermediate behavior takes so much extra logic. It would be nice if the Properties section of the Interactions panel had more than just the basics (selected / unselected)