Well I crunched the numbers and found that its actually faster to go from Santorini, to the Dam, then the Dam to Astrape. You might save power by going the Santorini to Astrape route, but its faster to go the other way. With only one loop (so the 1.2x multiplier), you save about ~2.5 minutes of time going to dam then to Astrape, rather than Santorini to Astrape.
However, I never figured out how to get the optimized route for Santorini to Astrape, so its possible with the optimized route, its actually faster.