weird slow start to manysketch

[ctb]

When running against ~2m ATB run accessions, it took about 8-12 hours to actually start reporting on which files it was trying to load.

was it doing manifest loading first (with silent failures) or something else??

either way... worth exploring.

[ctb]

note, this is before output CSV file is opened, it seems. so I think it's building the manifest. what happens that takes a while before manifest opened??