That is a nice feedback and quite true about vivy hmm.Changing her model now would be stupid because that would result in the same problem that you before with the change in resolution. If you change her model you would need to rerender all her scenes or it looks weird having her first with big tits and then suddenly with small ones.
I say if you are willing to do that then you also should have rerendered all low res images from the first part and not split the game into two parts.
But hey you already did multiple annoying things with your game so why not add more to it.
For the low res image part, unfortunately i have lost access to most of the save file for that render as my harddisk suddenly decides to malfunction. Not backing it up was my fault.
In future I'll re-render it.