Repeating the same formula again would be a bit predictable, and imho, this game has the potential to surpass Dr.'s previous work in all regards. And I also believe that including a harem route, by ridiculous that it would seem in real life, would really satisfy many, many fans. It could be like an unlockable route that would be achieved after clearing all the others. The work would be practically all done. What the Doc would have to do, imho, would be to just deliver every individual route (more like double LIs in this case), avoiding any paradoxes that could occur, and just add one big final scene where the harem would occur, like celebrating the completion of the masterpiece. A prize for all, even if it would be in the form of a DLC or a MOD.