Primary training is primarily learning to land. I learned in a 2-22 with aero tow, doing about two landings each Saturday because others went up also. A quicker way to do circuits (landings) is needed. A motorglider is obvious, but not so simple to do in practice. Later the club got a 2-33 which allowed advanced thermaling instruction which was a limiting factor with the 2-22, since one wrong turn and it needed to land. Perhaps the primary trainer could have a switch for advanced glide ratio. Electric thrusters can provide any glide ratio relatively cheaply without the need for large wings that are heavy.