Running two models for free will be heavy financial burden for devs i guess.

Lol

Or sometimes random letters get added

Nah, you are absolutely wrong. The new model is hundreth time better than previous one . It just needs training on more data. Or they can replace it with sdxl . I wouldn't mind paying for sdxl but the previous sd1.5 was very bad . I would agree if you say some art styles were masterpiece but we can get such art styles in this model too after the training finishes so be patient.