My wish-list of what should be feasible today:
*Pylon or shoulder wing. The Mü31 or a bit more radical.
*Ditch Schempp-Hirth drag brakes. They are heavy, complex and require an enormous amount of man-hours to build. Use "crow-foot" flaps instead, a bit like the AS system, but much more extreme.
*3-piece wing that's mounted on top of the fuselage. By using such a mid-wing you can drastically reduce structural wing mass.
*Use the above to build a 10m2 wing with an AR of 45-50 that's no heavier that today's racing class. Easily do-able with a sparless center wing and pultrusions.
*FES, with a raised main gear so you can take-off.
*Reduced battery pack for the FES. Replace that with a 5 HP 4-stroke generator and you loose all drawbacks of FES.