Is there any way to disable waypoints through circuit conditions, or is that a possible feature? I want to use the spidertrons much like trains, and turn off docks when there's enough stuff in the chests.

Thanks for the suggestion. That isn't currently possible because there is currently no connection between waypoints and docks. This is to simplify the internal code (they are implemented completely separately) and reduce the complexity of the mod for users. It also allows easy patrolling to positions where there aren't any docks since it works identically.

Maybe I'll implement a proper connection between waypoints and docks at some point, which might then allow me to implement this feature, but it won't be any time soon, sorry.