Most the time when I add anything I add the ingredient at he last 5 minutes of boiling. I’ve done his with orange peel and coriander for wit beers, berries for multiple styles, salt for gose’s.
I have been reading though about people pitching entire goodbelly probiotics in their beers, but I think they are going for more a sour character than citrus.
For most things, I like to add in the boil, and would add the purée in the last five minutes, just to kill off anything I did not really expect to have in the beer.