I've been on a quest to figure out how to get the black horse and have Nilfgaard win the war without getting the empress ending. After a fair amount of digging and deductive reasoning, I found that q110 is the ID for the quest this happens in (it also seems to be the ID for a DLC quest which made this a lot more difficult than it needed to be), after looking through the facts associated with that quest ID and fiddling with adding and removing these flags. I found the singular flag that determines whether you have the black horse. "q110_geralt_refused_pay". Regardless, having the option to have the black horse at the start of the game is still excellent.
I've been on a quest to figure out how to get the black horse and have Nilfgaard win the war without getting the empress ending. After a fair amount of digging and deductive reasoning, I found that q110 is the ID for the quest this happens in (it also seems to be the ID for a DLC quest which made this a lot more difficult than it needed to be), after looking through the facts associated with that quest ID and fiddling with adding and removing these flags. I found the singular flag that determines whether you have the black horse. "q110_geralt_refused_pay". Regardless, having the option to have the black horse at the start of the game is still excellent.