With a nothing Avisynth script, I just checked the file itself … to be sure. And it looked fine (no ghosting)! Double checked the file directly and no ghosting, too. I’m glad of that, but …

After stripping away individual statements to check that sequence (it was a pain on this under powered laptop), the problem turned out to be a 24fps “conversion” instead of a 24fps “setting”. (Who would’ve thought 24fps-to-24fps would produce a rounding error instead of being “transparent”? Well, at least I’m good at finding bugs.)

Hope I caught this soon enough to prevent any inconvenience on your end.

Of course, now, I must verify all my previous synchronizations …

UPDATE: The frame numbers of that sequence match with the script correction in place. Complete disaster averted!