Giving up thrust will help any time, you get to find the effects during flight, when it is going faster it wants to climb a bit then you push the Elevons down a bit then back to normal cruise speed ( 2/3 throttle ) all is back to normal trim.
These tailess airplanes are a diferent animals and your Stingray will fly a bit different than mine or my friend's, but it will fly and it will scare the pants off you
and you are going to want more of that for sure because, it will be so much fun to fly her.