The maximum cockpit weight question came up recently in regard to Dean Carswell's and my Flight Test of a DG-1000S recently, and after researching it we posted the folling reply:

"JAR-22 requires a minimum max cockpit design loading of 180 kg for
a two-place sailplane, but the designer can
indeed design and certify to a higher maximum, if he
so desires. The manual for the DG-1000 that we flight
tested last spring stated that the total, both seats
loading should not exceed 210 kg.

Since I flew the test flights with John Earlywine,
we were close to, but did not exceed the 210 kg limit.
Between the two of us with parachutes, we totaled
about 205 kg."
Dick JOhnson