I just tested a game with the Arcane mod (cheat mod) to give me 20 Zoology and 100 intelligence to always suceed on exchange familiars here's what i got.
Each time you use the "Exchange familiars" action, your current familiar is deleted and a new exotic one is added, never repeating. I used enough so i cicled the exotic familars to the point that i had no familiars and could not get a new one from that action. no crash or anything, just rendered the action useless.
So what this mod does on that regard, is if i use exchange familiar with Alice, i delete her and end up with no familiars, not that i would want to exchange the doll on the first place with this mod, but it was good to know how Exchange familar worked