New Area Transition markers

Is it possible to make them interactive/clickable? I just think that would be more intuitive if it isn't a terrible lot of work.

It might be possible, but I'd rather not. Doing so would involve some scripting (not a problem there), but could very likely prevent NPCs/monsters from chasing PCs through those doors/transitions if they try to run away (which happens with normal transition triggers and doors, and makes enemies slightly more intelligent/dangerous).