After playing for a relatively short time, (only two complete playthroughs) I discovered a few glitches that might be handy if people wish to experiment in the future.

In the stairway's next to the east and west wing, it is possible to use the stairs as a boost and clip through the ceiling into the wing. This can obviously get you straight to the main castle key, speeding up the Any% immensely. However, there are a few drawbacks. 1: Without east/west wing keys, you aren't able to exit the building, meaning there needs to be a glitch getting out. 2:Lack of supplies may make the West Wing much more of a slog. On another note, if you are able to glitch through the West/East Wing, who's to say there isn't a glitch for the main castle, too.

Just food for thought.