Fuse filters require more than two elements in a set. For example, if a block contains only one element, an upper layer on top of the fuse filter must handle that case.
This wasn’t critical for the benchmarking, so I just fidnt implement this logic yet. It’s an easy fix.
Regarding re-seeding: as far as I recall, it didn’t occur in the 50k mainnet dataset, but give me some time, I’ll need to verify once I have access to my laptop.