My DD has multiple allergies, some were discovered at 6 months, others like wheat at 11 months.
I breastfed her and I'm still breastfeeding her, and we are both on a dairy, soya, egg and wheat free diet.
I was very very pro breastfeeding and despite the numerous major obstacles, really fought hard for it. But in all honesty, I don't think it was worth it. If DD was on neocate from the start, it would have saved us so many tears and restless days and nights, and my sanity. Even now, at 14 months, I desperately wish she would take other milk that isn't breast milk, and she completely refuses to.
I was due to go back to work at 6 months and I've had to delay work as she is completely refusing to take the hypoallergenic formula (which was her only option). After 12 months, the dietician said she could take coconut milk but she doesn't want it. I'm at the end of my tether with the every 2 hour at night awakenings.
It is also so easy to make a mistake as a breastfeeding mother to eat the allergen. On top of that, you can't take something like piriton to get rid of the allergen from your body, you have to wait weeks for it to go, and it continues to harm baby!
Whereas if they are on hypo formula you don't have to worry about that, and when they are weaned and they may accidentally eat something, you can give piriton and it will work instantly.
If I were you I would look at it like you are giving your baby the best. If the specialists are of the opinion that hypo formula is best for your daughter, then you must give her that, as that is the best for her.