No way for me to know yet. More than the two days so far and less than the year it took the dev to write it. Honestly, there's just no way to calculate that yet since I'm not done coding the basics of the mod into the core.
I've finished the ChoiceGuide (including phone messages, Rooster, etc) and the base FreeRoam guides. I'm still working on MiniStat choreography, minigame coding, SanchoGallery population, and other UI tweaks/features. That's too much on the plate to know
The cake is still baking. But know that every major VN release takes more than two days bud, it takes one full day just to port over mod code and start analyzing the VN for it's changes and issues (bugs). There's literally over 500 script files and almost 200 choice menus alone to process... that's no short list by any VN standard.
So yeah, no need to be that guy... not yet. I'm not behind schedule tbh, I'm actually ahead by BaDIK update standards.