That's not a new plane, that's the double fuselage version of Pipistrel Taurus: https://en.wikipedia.org/wiki/Pipistrel_Taurus
Pipistrel Taurus is a glider, first flown in 2004. There is an added benefit of using a glider for testing a new engine: gliders have a much better L/D ratio, so less power needed for longer flights, and if there is a malfunction they can land safely while gliding.