1) When you use Aegisub’s resample resolution, it will typically output things with decimals. \pos tags with decimals aren’t read by libass at all.
2) Libass and/or Freetype and/or [something] apparently has no glyph substitution. Instead, it will crash if the font doesn’t have a glyph.
3) Libass coding is very shitty. Too many overrides on one line, even if the line before it had more, can cause it to crash for some people. For others it will work perfectly fine… (Maybe it’s an update/build issue?)
4) The Schneizel Solution — “If there’s a problem, then blow it up” — is probably better than trying to actually fix something.
5) DON’T EVEN THINK ABOUT MOTION TRACKING IN THE OPENING OR USING ORDERED CHAPTERS FOR A SHAFT SHOW. THEY LOVE CHANGING OPENINGS AND ENDINGS. D:

1: go pester amz at http://blog.aegisub.net/
2/3: LOL LIBASS
5: LOLSHAFT.