openstreetmap - Add vertices costs to postgresql routable network

In osm2po it's possible to create custom routers as the sample router TrafficSignalsRouter, but the costs seem to be added on vertices after the routing.

Is it possible to add these costs on the edges so that I can export them into my postgresql database (1 minute for each traffic signal in this sample)?

(by the way the vertices costs seem to be taken into account because it changes the generated path, but the final cost remains the same in the logs)