Using the OOB from the castle, I was able to get factory to load in, including the broken parts of the bridge leading to it but I was already so low that I ended up in a falling loop shortly after.
Does anyone know where the actual loading trigger is for that area?

Also is there a way to see hitbox information, or is anything in the works?

There isn't, at least I firmly believe so. I have tested it for hours.

The only way to get to factory is to first put the chalice into its place after getting all 4 flasks this then moves the elevator down and loads you into a new map that has the factory on it so there is no way to get to factory withought useing the chalice first