MJ, there are moves afoot (at last..) to bin the unworkable 'rolling validity' system. As we did with the NPPL.
Ze Tchermans insisted that it had always worked well for their gliderists; however, an amiable Mark Benton look-alike from the German CAA told us at a recent meeting that, in fact, German glider pilots were just as bad at ensuring their validity as everyone else. Which surprised me somewhat.