Android uses smaller breasts in form 2 so she can appear more human looking, but she can still increase her breast size and I will be including that during sex options.
Jin starts on a lot of drugs and hormones, some of them change her body. She was originally made to have the body of a thicc dark elf. Most common elves are petite like Lin or Jia. Nia would be considered fairly thicc for a common elf without any enhancements.