Hello,
The difference between setting parameter currentTravelTimes to True or False is only apparent when there is congestion in the network.
With 'False', empty-network travel times are used (or times loaded via option --weight-files).
With 'True', travel times are set to current average travel times on each edge (the value of edge.getTraveltime(). Note, that this may be quite volatile due to traffic lights and other effects.
The issue with begin and end time of addapted traveltime is, that the routing algorithm uses time-dependend weights:
If edge is fast now but it is already known that it will be congested in 5 minutes, than the vehicle will try to avoid routes that go past that edge by the 5 minute mark (taking travel time along that route into account). Therefore a time window of 1 second takes no effect.
You can reset the traveltime of an edge by calling setAdaptedTraveltime(vehID, edgeID). I suggest you keep a list of edges that you modified and reset this list after you are done with rerouting. Unfortunately, there is no simpler way at the moment.