I guess main focus for vanilla would be play day limit extension (from 300 seconds to 900 seconds)/100 day limit with payment extension. I know some people probably wouldn't like that, but that's a plan.
Extended customization options are planned too, but I can't guarantee I'll implement a lot there. Main focus is optimizng current assets keeping resolution and CPU/GPU usage as low as possible. Additional assets will make skeleton assets heavier and complicated to control.
Fetus count might be increased to 5 for base game. "Maybe" because it's a lot, but otherwise 4 and 5 belly sizes during pregnancy will be available in CB only.
One thing I'm not happy about is a overall reliance on BepInEx to work properly. Original V2 didn't use that, but V3 won't render slaves properly I'm afraid (BigBellySupport mod IS requered now).
Superior_keyaru
I'm afraid it won't happen, since original dev have his account set in private mode and we can't track his presence on this site or contact him. I did asked him to make this mod open source, but he refused.