Sorry but what are you talking about? very few female characters in the game break from the average listed in the codex . Like you're deliberately ignoring every female character in the game with small to average breasts, like...
Ethryn
Atugia
Kiyoko
Azzy
Agni
Jen
Janeen
Lusamine
Gytha
Daliza
Just to name a few.
I admit Ryn, Atugia, Agni, Kiyoko, Jen, Janeen, Lusamine, Gytha, and Janeen are within average of their race. Janeen is in average considering lupine as a race averages C-EE. But Azzy and Daliza aren't.
Azzy is supposed to have F cup breasts while in hive knight form and H cups in bimbo form. The bust art doesn't seem to reflect that. Also, according to what happened to her hive (the corruption/Kas demon shenanigans) and the codex for hornets, she is not the average. Beefolks are supposed to have larger breasts than hornet due to producing a lot of honey.
As for Daliza, she is also not the average because average breast size for boreal elves are B-D. Looking at her bust art, she is at least E-F cup and even checking her code for breast size, she is supposed to be G cup( i know those data aren't the most accurate and their writing/descriptions are the ones I should read but still).
Now I do know there are several others that wasn't mentioned that are within their average considering their race like tamarind, kohaku, rindo, etc. I really shouldn't have said all but I'm saying MOST female characters all have pretty much same figures: amazonian or slim hourglass. My point is that there's not much variety in body shapes.