Nope. If you want to to have Kat in the game and collar Bree, do the whole gamer side until the quest moves to completed, then run the following command:can we finally collar gamer bree yet?
Code:
DONE.pop("bree_event_05")
So far nothing broke for me and I finished both Kat and Bree.
This might break on later updates when more content is added for either of them tho.