Just stumbled over this on github:
https://gist.github.com/efonte/ce0b3a8f2651d2263d7085b2121d9f6c
Raw TXT

Looks like a complete export of the text/dialogue, minus the environmental/item and thought descriptions, I think.
Could be something to work with if ZA/UM don't get around fixing the typos/misspellings/grammatical errors themselves.
The python script used to extract/export maybe could be modified to insert/import a corrected version of the game's script instead.