Um, that's not why. She doesn't go for the cleavage-baring stuff because she has a scar on her chest, the result of injuries so severe that magical healing couldn't erase all the damage. Her being allergic to magical potions (and it's only potions) is an entirely different issue. She can use other magical means just fine:
They can and they do. I may be dreaming this up but it seems I read in the books most sorceresses started out as ugly ducklings, so their first order of business was altering their appearance. But if it's something major such as what happened to Triss, it may be irreversible. I feel CDPR made a practical decision in the first game and omitted the scar.
They can of course create illusions and the like, but permanently altering themselves physically is implied to be fairly difficult, and tends to leave subtle indications. Geralt for instance deduces Yennefer was once a hunchback because her shoulders are slightly misaligned.
Well, the scar is supposed to be pretty faint, so that may have been difficult to pull off well. Still, they couldn't resist tarting her up in that silly outfit with massive cleavage and fishnets.
In Blood Of Elves, she states she's allergic to potions/elixirs only. She can use other methods just fine. How else do you think they healed her after she almost died at Sodden? She was so fucked up as to be unrecognizable. That ain't a bed rest and bandages situation.
@Gilrond as @didymos1120 said, there is a explain for this a few posts ago. He posted it but for all who are might be
to lazy to read through
The scar Triss have on her chest isn t physical, its just an psychical issue because of the trauma she expierienced
in the battle. So i already told you guys people change during time, i think at last she overcomed this issue
Specially after nilfgaards interogation... and so on
I've always understood physical scar too.
Yeah, it's definitely physical. Don't know why that guy said that I didn't think it was. What I (and Triss) said is that it wasn't a super prominent scar:
I.e. it's noticeable enough to remind her of what happened and make her self-conscious, but it's not like one of Geralt's crazy scars.
No, her allergy wasn't mentioned in that context. It came up quite a bit later when she caught some sort of stomach flu. The damage was simply so bad they couldn't get rid of all the scarring.
