The ensemble didn't earn its keep
All 7 index subsets, 1,500 bilingual queries, paired bootstrap at 10k resamples. Every recall difference sat inside the noise; the 3-index ensemble was significantly behind a single index on MRR@10. We ship one — a third of the memory, a third of the search time.
ENSEMBLE − metadata_128 · R@10 +0.0047 [−0.0076, +0.0168] · n.s.