I first noticed with Billie Eilish that it's really challenging to tune the female physique in Flux for anything other than fairly unrealistic ideals.
You need to pump a lot of tokens in to prevent it from being the same:
A) Anorexic catwalk model
B) Strangely well endowed teen
C) Chunky
D) Heavy
I think those are the four builds they trained on. And I'm usually OK with tweaking the A's and the occasional B's with words and Loras but the C's and D's are wild, untamable beasts. And for any starting point that doesn't fit neatly into A, B, C or D the results seem completely random.