A Glider rating using a Motor-Glider capable of Self Launch is a good way to accomplish the initial rating. You should be able with the Pipstrel be able to ger a firm grasp of thermal, wind effects, ridge lift, etc. You will get a better understanding of local weather and what the air is doing. There are not many places to rent a motor glider. Most glider operations in the US are pure gliders with either Aero Tow or Ground Launch.
Additional launch methods of Aero Tow, and Ground Launch, are simple instructor endorsements. Additional check rides are not required. Depending on your proficiency and experience with formation flying, aero tow may take some getting used to with proficiency of the "emergency procedures on tow".
Any glider, with any self propulsion capability, whether self launch or sustainer, must be flown as if that engine is not going to start. ROTAX engines are very reliable, but there are instances of failed air starts for various reasons. Low Battery, failed starter motor, once the propellor has changed from low drag soaring mode, to let's get the engine started mode, that is a lot of drag, comparatively. There best be someplace you can land, true glider style, with no propulsion.
